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TECHNICAL  ART  5f RI  B5. 


POTTERYTFORARTISTS 


THE  MACMILLAN  COMPANY 

NEW  YORK  •    BOSTON  •   CHICAGO  •   DALLAS 
ATLANTA  •   SAN  FRANCISCO 

MACMILLAN  &  CO.,  LIMITED 

LONDON  •    BOMBAY  •   CALCUTTA 
MELBOURNE 

THE  MACMILLAN  CO.  OF  CANADA,  LTD. 

TORONTO 


He  wrought  a  work  upon  the  wheels,  and  the  vessel  that  he  made  of  clay  was 
marred  in  the  hands  of  the  Potter :  so  he  made  it  again  another  vessel,  as 
seemed  good  to  the  Potter  to  make  it."  —  (JEREMIAH.) 


rTERY, 

mmwcMcmwHomm 

FOR  ARTISTS 
CRAFTSMEN 
^TEACHERS 


GEORGE-J-COX-AiLCA. 

INJTRUCTORjnf  OTTtKY^  AVODELLING- AT 
TEACHERS  COLLEGE-COLOMBIA.  UNIVERSITY3' 

ILLUSTRATED  V^  AUTHOK 


YORK 

THEMACMILLATM  COMPANY- 
LONDON:  MACMILLAN  ^ 


C> 


COPTKIOHT,   1914, 

BY  THE  MACMILLAN  COMPANY 
Set  up  and  electrotypcd.    Published  November,  1914. 


Xorfoooti 

J.  8.  Gushing  Co.  —  Berwick  &  Smith  Co. 
Norwood,  Mass.,  U.8.A. 


"  O  Master,  pardon  me,  if  yet  in  vain 
Thou  art  my  Master,  and  I  fail  to  bring 
Before  men's  eyes  the  image  of  the  thing 

My  heart  is  filled  with." 

—  WILLIAM  MORRIS. 


358905 


EXPLANATION 

IN  such  a  spacious  craft  as  Pottery  it  is  difficult 
to  steer  a  fair  course  between  the  empirical  and  the 
scientific.  With  that  in  mind  this  book  sets  out  to 
tell  in  simple  terms  some  of  the  processes  of  Potting, 
practicable  to  the  student  and  to  the  more  finished 
craftsman. 

It  is  an  intricate  task  to  combine  successfully  the 
view-points  of  the  artist  and  the  scientist;  but  it 
seems  that,  without  neglecting  the  many  benefits 
bestowed  by  the  advance  of  science,  the  Potter 
should  stand  with  the  former.  The  best  in  his 
craft  has  been  produced  by  men  that  were  artists 
rather  than  chemists.  And  what  has  been  accom- 
plished by  loving,  patient  craftsmanship  may  surely 
be  done  again  only  in  such  ways. 

To  the  artist  craftsman,  for  whom  chiefly  this 
book  is  intended,  a  little  scientific  knowledge  is  a 
dangerous  thing;  for  that  reason  no  great  stress  is 
laid  on  formulas  and  analysis.  Unless  thoroughly 
understood  they  are  a  hindrance  rather  than  an  aid. 

Although  many  schools  teach  elementary  pottery, 
the  expense  of  equipment  possibly  delays  its  intro- 
duction on  a  larger  scale.  For  that  reason  I  have 
preferred  to  err  on  the  side  of  over-exactness  of 

description  and  prof usen ess  of  illustration. 

vii 


vm 

The  slight  historical  review  and  introductory  re- 
marks are  to  be  excused  on  the  ground  that  they 
are  intended  to  help  to  a  study  of  the  best  work  of 
the  best  periods,  and  so  to  foster  a  taste  for  the 
finest  Ceramics.  This  is  a  vital  matter  when  lay- 
ing the  foundations  of  a  craft  so  fascinating  and 
so  full  of  alluring  avenues  to  beckon  the  student 
from  the  true  path. 

To  the  scientific  critic  I  would  offer  a  hundred 
books  with  a  thousand  different  compounds ;  amongst 
none  of  them  will  he  find  how  to  make  a  Sung  bowl 
or  a  Rakka  drug  pot. 

This  book  will  achieve  its  purpose  if  it  sets  one  or 
two  sincere  students  to  the  making  of  some  of  the 
many  beautiful  objects  of  utility  and  art  with  which 
the  craft  abounds.  Then  it  will  have  done  some- 
thing, if  never  so  little,  to  accelerate  the  arrival  of 
that  time  when  the  artist  will  come  once  more  into 
his  own  in  the  most  ancient  and  noble  of  Crafts. 

Some  of  the  many  books  consulted,  to  which  I  am 
indebted,  are  given  at  the  end  of  the  book.  Among 
friends  my  thanks  are  especially  due  to  Richard 
Lunn,  Esq.,  of  the  Royal  College  of  Art,  London, 
and  to  Professor  Arthur  Wesley  Dow  of  Teachers 
College,  Columbia  University,  for  my  introduction 
to  and  opportunity  of  further  study  of  the  Craft  to 
which  I  subscribe  myself  an  humble  devotee. 

G.  J.  C. 


TABLE  OF  CONTENTS 

MOB 

EXPLANATION vii 

CHAPTEB 

I.    HISTORICAL  SUMMARY 1 

II.    CLAYS  AND  PASTES 19 

HI.    BUILT  SHAPES        .        .        .        .  ,      .        .        .26 

IV.    MOULDING,  CASTING,  AND  PRESSING       ...  34 

V.    JIGGER  AND  JOLLEY  WORK 51 

VI.    THROWN  SHAPES 59 

VII.    TURNING  OR  SHAVING 73 

VIII.    TILE-MAKING 80 

IX.    DRYING:  FINISHING 89 

X.    FIRING  BISCUIT 93 

XI.    GLOST  FIRING 107 

XII.    GLAZES  AND  LUSTRES     .        .        .        .  .117 

XIII.  DECORATION 129 

XIV.  FIGURINES 141 

XV.    KILNS 151 

XVI.    THE  EDUCATIONAL  VALUE  OF  POTTERY  .        .        .  170 

APPENDIX  I.    EQUIPMENT  FOR  A  SMALL  POTTERY  OR  A 

SCHOOL 177 

APPENDIX  II.    GLOSSARY  AND  GENERAL  INFORMATION  185 


and  modern ;  for  it  is  a  truism  that  however  handily 
a  craftsman  may  work,  his  output  will  be  worthless 
if  he  has  not,  with  his  increasing  powers  of  technique, 
developed  a  sound  judgement  and  refined  taste. 
To-day,  these  alone  can  replace  the  lost  traditions 
of  the  old  masters. 

The  Potter's  Craft  had  a  coeval  birth  in  various 
parts  of  the  earth,  but  the  obscurity  is  such  that 
no  clear  idea  can  be  gained  of  its  antiquity.  It  was, 
probably,  the  first  form  of  handicraft,  if  we  except 
the  fashioning  of  flints  and  clubs.  Accident  or  the 
funeral  pyre  may  have  suggested  the  extraordinary 
durability  the  clay  shape  obtained  when  burned, 
and  doubtless  siliceous  glazes  were  first  the  result 
of  chance.  All  early  work  was  built  up  by  hand  and 
for  that  reason  possesses  wide  mouths  and  simple 
forms.  The  introduction  of  the  wheel  is  lost  in  a 
mist  of  time,  but  drawings  from  the  tombs  of  Beni 
Hassan  show  the  potter  at  his  wheel  substantially 
as  he  works  in  Asia  to  this  day.  The  wheel-made 
or  thrown  shape  is  distinguished  by  far  more  grace 
and  symmetry  than  the  built  shape,  and  by  an 
infinitely  greater  variety  of  form. 

In  burial  mounds  from  prehistoric  Egypt  are  found 
many  bowls  and  platters  rudely  scratched,  and  the 
earliest  examples  from  mounds,  lake  dwellings,  and 
tombs  show  the  quick  development  of  the  pot,  not 
only  as  an  object  of  utility,  but  as  a  vehicle  of  art. 


The  first  kinds  of  decoration  were  incised  lines  fol- 
lowed by  strappings  and  bandings,  painted  stripes 
and  scrolls  and  hieroglyphs,  with  later  additions  in 
slip  and  modelled  clay.  Primitive  wares  from  their 
method  of  production  exhibit  an  interesting  similar- 
ity of  shape  and  style  in  such  widely  divergent 
countries  as  China,  Egypt,  and  Peru. 

It  was  only  when  the  craftsman  had  acquired  con- 
siderable dexterity  that  we  find  his  nationality  influ- 
encing his  shapes  and  producing  the  wonderful 
variety  in  form  and  decoration  that  characterizes 
and  distinguishes  the  pottery  of  all  nations.  Once 
established,  the  prevalence  of  type  is  strong.  This 
traditional  style  is  particularly  noticeable  in  Egypt, 
much  modern  work  being  identical  with  that  of  the 
early  dynasties. 

Before  turning  to  more  sophisticated  work  it 
would  be  well  to  learn  the  lesson  of  simplicity  and 
fitness  here  taught  by  primitive  folks.  The  simple 
beginning  leads  to  the  simple,  strong,  and  satisfying 
end.  Much  of  this  primitive  work  is  inspiring  for 
its  freshness  or  naivete;  its  unspoiled  innate  taste 
allied  to  downright  common  sense.  Properly  ap- 
proached, it  should  be  a  sure  corrective  to  any  desire 
for  unsightly  new  shapes  or  extravagance  in  deco- 
ration. A  few  careful  studies  will  do  much  to  drive 
home  this  valuable  lesson  in  fine,  simple  line  and 
spacing. 


In  Egypt  the  thrown  shape  was  not  distinguished 
by  any  extraordinary  beauty  or  variety.  Never- 
theless their  small  Ushabti,  glazed  gods  and  demons, 
show  a  very  advanced  knowledge  of  coloured  enamels, 
and  their  fabrication  of  a  hard  sandy  paste  for  glaz- 
ing shows  the  first  great  step  in  the  science  of  pot- 
tery. Their  glaze  was  purely  alkaline. 

The  Assyrians  appear  to  have  been  the  first  to 
use  coloured  tin  glazes,  and  although  few  pieces  of 
pottery  survive,  the  enamelled  friezes  from  Korsobad 
and  Sousa  are  striking  evidence  of  their  proficiency 
in  tile  making. 

From  Egypt  and  Mesopotamia  the  craft  spread 
east  and  west  to  Phoenicia,  Attica,  and  Greece; 
through  Persia  and  Arabia  to  India.  Here  it  mingled 
with  currents  from  China,  then  invading  Korea,  Japan, 
and  Siam,  the  united  floods  rising  until  the  potter 
was  a  power  in  every  land. 

Phoenician  pottery  forms,  with  Cretan  and  early 
Grecian,  a  beautiful  sequence  from  the  primitive 
work  of  early  dynasties  to  the  refinements  of  later 
Grecian  wares. 

It  will  prove  an  interesting  and  instructive  study 
to  trace  the  developments  that  led  finally  to  the 
zenith  of  Greek  pottery.  The  primitive  Hissarlik 
ware  leads  through  Mycenean,  Dipylon,  Phalse- 
ron,  Rhodian,  and  Corinthian  right  up  to  the 
wonderful  figure  vases  of  about  300  B.C.  Although 


limited  in  paste  and  colour,  with  a  thin-  trans- 
parent glaze  or  lustre,  these  vases  were  exquisitely 
fashioned.  Large  and  small  shapes  of  wide  di- 
versity were  decorated  in  black,  red,  and  white, 
ornament  and  figures  both  drawn  straight  on  to  the 
body  with  a  sureness  of  touch  and  refinement  of 
line  that  excite  the  envy  of  a  master.  Many  of 
their  forms  are  strongly  influenced  by  contemporary 
bronze  work  and  for  that  reason  are  not  the  best 
guides  for  shapes.  Their  incomparable  terra-cottas 
known  as  Tanagras  form  a  link  between  Pottery  and 
Sculpture. 

Again,  from  Phoenician  work  one  may  see  dimly 
by  way  of  Samian,  Rhodian  and  old  Cairene  wares 
the  lineage  of  the  royal  wares  of  Persia,  and  recent 
investigations  point  to  Old  Cairo  as  the  birthplace 
of  lustre. 

From  Persia  come  some  of  the  finest  pottery, 
painted  in  colours  and  lustres,  that  the  world  can 
show.  Their  wares  stand  pre-eminent  in  that  class 
wherein  the  chief  beauty  is  the  painted  decoration. 
Their  one-colour  pieces,  whilst  not  comparable  with 
the  Chinese,  nevertheless  reach  a  high  standard. 
Their  lustres  have  never  been  surpassed  or  rarely 
equalled.  Their  shapes  are  true  potter's  shapes,  and 
a  delight  to  the  eye.  The  finest  pieces  were  painted 
in  simple  blues,  greens,  reds,  and  faint  purples,  with 
black  pencilling.  This  appears  to  have  been  done 


6 

on  an  engobe  of  finely  ground  flint,  and  covered  with 
an  alkaline  glaze  giving  a  broken  white  ground. 
This  would  account  in  some  measure  for  the  ex- 
traordinary freshness  of  both  drawing  and  colour. 
Later  on  raised  ornament,  finely  conceived  and  used 
with  restraint,  is  seen  along  with  pierced  decoration 
having  translucent  effects. 

Rhodes  and  Damascus  produced  a  somewhat 
coarser  ware,  but  bold  and  free  in  brush  work  and 
varied  with  a  bright  red.  Syrian  pottery  abounds 
in  virile  individual  shapes.  Turkey  also  was  not 
without  a  fine  and  vigorous  style. 

Much  time  can  be  most  profitably  spent  study- 
ing the  masterpieces  of  Persia.  A  representative 
collection  like  that  at  South  Kensington  will  show 
vases,  bottles,  bowls,  pots,  and  tiles  in  bewildering 
variety  and  of  infinite  freshness.  They  are  directly 
painted,  with  free  renderings  of  flowers  within 
geometric  forms  and  often  with  an  inscription  in 
rich  Arabic  characters.  The  exquisite  Moore  Collec- 
tion in  the  Metropolitan  Museum,  New  York  City, 
is  smaller  but  is  remarkable  for  the  unusually  high 
standard  of  taste  shown  in  its  acquisition.  At  its 
purest  period  human  or  animal  figures  were  rarely 
or  never  represented  and  those  shapes  or  tiles  with 
such  decoration  belong  to  a  more  decadent  but  still 
fine  period. 

Again  we  have  the  eternal  lesson  of  simplicity  and 


fitness.  Again  it  will  be  borne  in  upon  the  student 
that  originality  does  not  mean  weirdness,  but  rather 
a  fresh  spontaneous  treatment  of  simple,  well-known 
natural  forms,  with,  above  all,  a  fine  appreciation 
of  good  line  and  space.  No  sincere  student  can 
fail  to  develop  here  a  respect  and  veneration  of  a 
craft  and  of  craftsmen  capable  of  producing  such 
glorious  works. 

From  this  teeming  home  the  craft  spread  to  Arabia 
and  west  across  the  Mediterranean  to  Spain.  Here 
in  the  twelfth  century  the  Moors  were  producing 
their  famous  Hispano-Mooresque  lustred  wares. 
Their  large  plaques  offer  a  wonderful  variety  of  pure 
brush- work  ornament  with  spirited  heraldic  additions. 
Sometimes  the  backs  of  these  dishes  are  as  beauti- 
fully lustred  as  the  fronts. 

For  a  proper  appreciation  of  their  purely  geo- 
metric decoration  and  its  possibilities  in  pottery  we 
must  turn  to  the  Alcazzar  at  Madrid.  Here  the 
use  of  opaque  tin  glaze  permitted  the  extensive  use 
of  a  coarse  body  for  tiles  and  bricks.  The  Moors, 
however,  first  introduced  glazes  with  a  lead  base 
and  from  that  time  we  begin  to  lose  the  fresh  wet 
colour  always  associated  with  the  alkaline  glazes 
of  the  Persians.  Analysis  shows  that  they  used 
lead,  but  only  occasionally  and  in  small  quantities, 
to  aid  their  lustres.  The  lustred  wares  of  Spain 
declined  late  in  the  thirteenth  century,  but  not  before 


8 

its  exportation  to  Italy  by  way  of  Majorca  had  stim- 
ulated the  production  of  Italian  Majolica.  Delia 
Robbia,  about  1415,  succeeded  in  colouring  his  tin 
glazes,  and  his  finely  modelled  but  somewhat  crudely 
coloured  reliefs  usher  in  the  era  of  Italian  Faience. 
Patronized  by  the  nobles  the  craft  quickly  took  root 
and  was  blossoming  profusely  at  Urbino,  Gubbio, 
Pesaro,  Faenza  and  other  cities  at  the  end  of  the 
fifteenth  century. 

Here  we  break  ground  and  leave  the  chaste 
simplicity  of  the  golden  age  to  riot  a  blaze  of  exu- 
berant decoration.  Scraffito,  slip,  inlaid,  applied, 
incised,  raised,  embossed  and  modelled  and  painted 
embellishments;  all  are  here.  This  era  is  chiefly 
notable  for  its  splendid  ruby  lustres  and  the  remark- 
able power  and  freedom,  amounting  to  absolute 
abandon,  of  the  brushwork  and  drawing  shown  by  its 
artists.  They  used  their  lustres  to  heighten  the 
effects  of  their  painting  and  the  results  are  in  keep- 
ing with  that  romantic  age.  Alongside  of  it  our 
best  modern  work  is  apt  to  look  spiritless  and  dull. 

Much  splendid  work  was  produced  in  Italy  at 
this  period,  but  in  such  a  wide  field  there  are  natu- 
rally some  places  that  exhibit  technique  rather  than 
art.  The  student  must  go  into  it  with  appreciative 
faculties  alert  lest  mere  splendour  should  sweep  him 
off  his  feet.  * 

The  wares  and  the  potters  of  Italy  penetrated 


9 

north  into  Europe,  to  France,  the  Holy  Roman  Em- 
pire and  Britain,  starting  or  stimulating  what  was 
to  prove  an  overwhelming  flood  of  production.  In 
Europe  in  pre-Roman  times,  a  coarse,  unglazed, 
built-up  ware  was  general,  it  being  of  simple,  some- 
what clumsy  but  vigorous  form,  low-fired  and  fri- 
able. It  was  used  chiefly  for  cinerary  purposes, 
the  Germanic  peoples  having  a  decided  preference 
for  vessels  of  horn,  wood,  or  metal. 

The  Romans  introduced  the  wheel  and  produced 
a  far  higher  class  of  ware.  Their  importation  of  the 
fine  red  Samian  pottery  resulted  in  the  fabrication 
of  the  vigorous  Gallo-Roman  and  Romano-British 
pottery.  This  was  good  in  shape  and  paste  and 
characteristically  decorated  with  slip,  bosses,  dots, 
and  indentations.  The  later  Gaulish  work  shows 
applied  figures  and  highly  finished  scroll  work. 
After  the  decline  of  Rome,  Saxon  and  Germanic 
work  shows  a  distinctly  retrograde  tendency.  It  is 
often  built  up,  strapped,  banded,  and  bossed  in  imi- 
tation of  the  Romano-British.  Though  coarse  and 
lacking  in  finish,  it  is  full  of  freshness  and  character. 

In  Mediaeval  England,  when  pottery  making  was  at 
a  low  ebb,  the  monasteries  and  travelling  guilds  of 
potters  produced  splendid  encaustic  tiles.  These 
were  inlaid  with  simple  yet  striking  geometric  de- 
signs, or  animal  01;  bird  forms,  both  heraldic  and 
symbolic. 


10 

In  Europe  for  many  years  the  domestic  pottery 
remained  coarse  and  primitive,  showing  still  the 
arresting  hand  of  the  barbarian  conquerors  of 
Rome.  The  first  signs  of  the  Italian  Renaissance 
are  to  be  found  in  the  rare  Henri  Deux  or  Orion 
ware.  Palissy's  desperate  and  romantic  search  for 
enamels  was  the  prelude  to  the  development  of 
Rouen,  Nevers,  Lille,  Moustiers,  Sevres,  Marseilles, 
and  other  less  important  potteries.  In  France  also 
early  experiments  led  eventually  to  the  fabrication 
of  porcelain  much  on  the  lines  of  English  porcelain, 
a  frit  being  used  instead  of  kaolin. 

In  Germany,  as  early  as  the  fifteenth  century,  they 
produced  fine  stoneware  highly  decorated  with  relief 
patterns  and  colours.  After  long  research  Boettiger, 
by  a  lucky  accident,  discovered  kaolin.  Porcelain 
was  made  at  Dresden  in  1709,  and  many  of  the  Dres- 
den figures  show  a  remarkably  sympathetic  alliance 
of  potting,  modelling  and  painting. 

The  success  of  the  German  ceramists  led  to  a  wide 
patronage  of  potters  by  kings  and  princes  which 
quickly  spread  the  knowledge  of  porcelain  through- 
out Europe. 

Long  before  this  in  the  early  part  of  the  seven- 
teenth century,  potteries  were  established  at  Delft 
in  Holland.  Here  was  made  the  well-known  ware 
painted  in  blue  camaien  on  a  fine  white  ground. 
This  was  for  a  time  produced  in  great  quantities, 


11 

and  the  process  of  painting  directly  on  to  an  absorb- 
ent ground  led  to  a  surprisingly  fresh  and  skilful 
style. 

In  the  middle  of  the  seventeenth  century  English 
wares  commenced  to  rise  from  the  stagnation  in 
which  they  seemed  sunk  since  Saxon  times.  Toft, 
with  his  tygs  and  platters,  Dwight,  and  his  bellar- 
mines,  and  Elers,  with  turned  shapes,  started  a  move- 
ment which  was  eventually  to  send  English  wares 
into  all  parts  of  Europe,  even  into  the  far  Russias,  to 
be  known  everywhere  for  its  excellent  workmanship. 
And  in  this  flood  of  production  in  the  seventeenth 
and  eighteenth  centuries  was  much  that  was  tech- 
nically unrivalled  despite  the  fact  that  the  Art  of 
the  potter  is  sometimes  far  to  seek.  Dwight  is  said 
to  have  produced  a  fritted  porcelain  in  1671,  before 
the  discovery  of  kaolin.  This  is  doubtful,  but  his 
persistent  research  eventually  led  up  to  the  fine 
pastes  of  Chelsea  and  Bow  and  the  unrivalled  "fine 
earthenwares"  of  Staffordshire. 

This  European  revival  gained  tremendous  impetus 
from  the  importation  by  the  Portuguese  of  the  wares 
of  CHINA.  The  wide  scope  of  its  decoration,  both 
painted  and  modelled,  pointed  the  way  to  most 
potters  of  the  West  during  the  heyday  of  European 
pottery.  The  magnificent  single-colour  pieces  were 
not  introduced  until  later  when  the  break-up  of  the 
Empire  rendered  them  accessible  to  Europeans.  It  is 


12 

to  them  that  the  student  must  turn  to  see  the  summit 
of  the  potter's  art,  which,  it  is  logically  contended, 
commences  on  the  wheel  and  ends  at  the  glost  oven 
with  the  potter,  the  only  attendant  from  the  pot's 
inception  to  its  finish.  Painting  or  modelling  is  not 
essential  to  its  perfection  and  unless  applied  by  a 
true  disciple  detracts  rather  than  adds  to  the  beauty 
of  the  piece. 

In  China,  where  tradition  holds  that  earthenware 
was  first  made  in  2698  B.C.,  the  art  of  the  potter,  in 
body,  shape,  glaze,  and  colour,  through  centuries 
reached  perfection.  Porcelain  is  said  to  have  been 
first  made  about  200  B.C.,  but  this  date  is  conjectural. 
What  we  do  know  unmistakably,  however,  is  that 
the  best  work  of  their  best  periods  is  unrivalled. 
Depending  primarily  on  form  and  colour,  with  here 
and  there  a  subtle  decoration  in  raised  or  incised 
line,  in  crackle  or  simple  brushwork,  it  stands  alone, 
and  despite  the  omnipotent  chemistry  of  to-day, 
defies  imitation.  Their  forms  are  strong,  bold,  and 
dignified,  yet  subtle  and  delicate,  too.  Then,  added 
to  a  wonderful  range  of  colours,  was  a  perfection  of 
body  that  was  for  so  long  the  despair  of  western 
imitators.  It  is  here  at  the  altar  of  perfection 
amidst  the  chaste  richness  of  Tang  and  Sung  and 
Ming  that  the  true  disciple  must  worship.  And  to 
those  who  must  eat  bread  as  well  as  make  pots  it 
is  to  be  pointed  out  that  these  pieces  at  the  time  of 


13 

their  production  fetched  prices  that  compare  favour- 
ably with  the  "  fancy  "  prices  given  to-day. 

To  the  Japanese  also  in  great  measure  the  same 
tribute  is  due.  Although  beginning  later  as  dis- 
ciples and  scarcely  getting  so  far  as  their  masters, 
their  more  limited  range  of  colour  and  form  is  set 
off  by  their  restrained  and  even  more  tasteful  deco- 
ration. The  unique  collection  in  the  Boston 
Museum  is  an  amplification  of  this  bald  statement. 
They  were  often  more  concerned  with  the  touch  and 
texture  of  the  pot  than  the  more  obvious  appeal  of 
decoration.  Esoteric  as  it  is  to  most  occidentals  it 
is  rich  in  a  pure  sestheticism  and  a  deep  and  beautiful 
symbolism  that  is  slowly  but  surely  having  an  influ- 
ence on  western  art,  just  when  it  seems  in  some 
danger  of  dying  out  in  Japan.  The  hermit  kingdom 
of  Korea,  despite  its  midway  position,  produced  pot- 
tery that  is  strangely  beautiful  and  distinctive  and 
worth  much  more  than  a  passing  notice. 

In  China  the  art  decadence  of  the  eighteenth  and 
nineteenth  centuries,  coupled  with  internal  revolu- 
tions, has  sadly  dimmed  her  plots,  dispersed  her 
potters,  and  all  but  destroyed  her  priceless  traditions. 

For  the  further  development  of  pottery  in  Europe 
and  America  and  Asia  the  student  has  many  excellent 
books  to  consult.  From  the  seventeenth  century  the 
ramifications  are  rapid  and  all-embracing,  giving, 
however,  more  joy  to  the  collector  than  to  the  artist. 


14 

Modern  work  has  made  an  enormous  advance  in  the 
science  of  the  craft.  Since  the  "Eighties"  it  shows 
signs  of  a  renaissance  in  aesthetics.  Lustres  of  all 
shades,  crystalline,  star,  and  crackle  glazes  with 
safe  methods  of  oxidizing  and  reducing  in  the  fire, 
have  been  brought  to  perfection.  Yet,  with  some 
few  exceptions,  commerce  seems  writ  large  upon  them 
all  and  their  very  perfection  of  finish  damns  them  in 
the  eyes  of  an  artist.  Whichever  way  he  looks,  he 
must  return  again  and  again  to  refresh  his  eyes  with 
the  inspiring  examples  of  the  best  that  has  survived 
from  the  near  and  far  EAST. 

Only  an  antiquarian  humbug  would  wish  to  go 
back  to  ancient  conditions  even  to  produce  old  pots. 
But  it  is  only  by  seeing  in  so  far  as  we  may  in 
museums  and  books  the  works  of  these  ancient  yet 
ever  modern  potters ;  by  tracing  their  development, 
appreciating  their  qualities  and  attempting  to  work 
as  they  worked,  honestly  anfl  unaffectedly,  that  we 
shall  begin  to  approach  the  excellence  and  originality 
of  their  art.  This  study  should  not  of  course  obey 
the  direction  it  all  too  frequently  follows.  The 
slavish  measuring  by  module  and  fraction  of  classic 
styles,  the  stark  geometric  analysis  of  Moorish  orna- 
ment or  the  laborious  copying  of  Chinese  pattern  is 
at  best  only  art  in  cold  storage.  It  should  be  self- 
evident  that  where  an  alien  style  is  consciously 
imitated  the  result  is  sterility  for  the  imitator. 


15 

In  others,  it  is  apt  to  produce  a  powerful  reaction 
that  results  in  Futurism  or  some  such  self-conscious 
affectation.  "The  Greeks  did  not  draw  from  casts 
nor  did  the  Persians  haunt  museums,"  says  the 
harried  student.  No.  But  better  than  that,  they 
were  surrounded,  if  not  by  beauty,  at  least  by  nature 
naked  and  unashamed.  They  lived  not  easily 
maybe,  but  surely  more  gracefully,  untrammelled 
by  fashion,  cult,  or  craze. 

"  The  earth  his  sober  Inn 
And  quiet  pilgrimage." 

Their  best  work  seems  ever  fresh,  spontaneous, 
and  untired.  It  must  have  been  done  with  a  spirit 
and  real  joy  impossible  to  anyone  but  a  true  crafts- 
man tremendously  interested  in  his  work,  we  might 
also  add,  his  environment. 

Naturally,  present-day  conditions  must  modify 
the  struggle  for  existence.  They  may  mar  our  best 
aim  at  times.  Yet  some  few  have  worked  wonders 
even  in  this  age.  To  mention  but  two  instances, 
W.  De  Morgan  and  the  Martin  brothers,  is  to  tell 
of  high  endeavour  and  great  achievement.  But  we 
must  not  expect  to  get  rich  that  way. 

Pottery  is  an  exacting  and  difficult  craft,  abound- 
ing in  as  many  trials  and  disappointments  as  excite- 
ments and  rewards.  Its  true  devotee  must  suffer. 
Yet  the  delightful  tale  of  Palissy's  heroic  battle 


16 

should  hearten  the  more  fortunate  student  of  to-day. 
It  is  good  to  read  of  the  spirit  in  which  Wedgwood, 
scientist  though  he  was,  approached  his  work.  In 
a  trade  catalogue  he  says,  "A  Competition  for  Cheap- 
ness, and  not  for  Excellence  of  Workmanship,  is  the 
most  frequent  cause  of  rapid  Decay  and  entire  De- 
struction of  Art  and  of  Manufacture."  "  Beauti- 
ful Forms  are  not  to  be  made  by  Chance  and  they 
never  were  made  nor  can  be  made  in  any  kind  at 
small  expense."  Such  sentiments  rarely  emanate 
from  the  modern  commercial  pottery. 

Tradition,  except  the  traditions  of  flawless  glazes, 
certain  soulless  results,  and  commercial  cheeseparing ; 
seems  dead  perhaps,  but  it  will  surely  come  to  life 
again.  To  see  the  potter  "thumping  his  wet  clay," 
and  seated  at  the  wheel  of  ancient  lineage,  conjuring 
forth  a  wealth  of  gracious  shapes,  is  to  renew  one's 
faith  in  the  ultimate  survival  of  simple  honest  handi- 
craft even  in  this  machine-ridden  age.  Masterpieces 
were  never  conceived  in  factories,  and  when  we 
make  pots  primarily  for  love  of  them,  not  to  sell 
them,  we  shall  begin  to  beat  back  the  manufacturer 
of  debauched  "Art"  pots  into  that  domestic  and 
hygienic  realm  wherein  his  efforts  are  particularly 
admirable  and  effective.  A  craft  that  teems  with 
such  an  endless  variety  of  beautiful  objects  for  such 
countless  uses  can  never  remain  for  all  time  the  hand- 
maiden of  commerce. 


flollou/ip^  tl?e  Ball 


CHAPTER  II 

AND  PASTES 


"It  is  the  Art  which  gives  the  value,  and  not  the  material." 

—  DRESSER. 

CLAY  being  the  chief  material  used  by  the  potter, 
it  demands  a  description  which,  without  being  too 
technical,  will  give  from  the  start  a  clear  idea  of  the 
nature  of  clays  or  pastes  in  general  use. 

It  would  be  a  needless  complication  to  enter  here 
into  a  discussion  of  the  chemical  analysis  of  bodies 
and  materials.  Whilst  the  chemist  can  and  does 
determine  with  exactitude  the  relative  quantities 
of  each  component,  he  cannot  yet,  let  us  perhaps 
be  thankful,  lay  down  with  the  same  certainty  the 
structural  and  molecular  changes  all  these  com- 
pounds will  undergo  in  the  fire.  The  old  potters' 
rule  "of  thumb"  or,  rather,  common  sense  and  ex- 
perience, still  count  for  something. 

Clay  is  the  word  generally  applied  to  the  natural 
article  when  used  without  preparation,  or  after  pick- 
ing and  washing.  Paste  is  the  term  used  for  all  com- 
posite bodies  that  have  been  through  a  complicated 
process  of  washing,  grinding,  mixing,  and  sieving, 

19 


20 

or  even  fritting,  according  to  the  desired  quality 
of  the  ware  for  which  it  is  required.  Natural  clays 
range  from  the  pure  white  and  very  infusible  kaolin, 
containing  only  alumina  and  silica  with  a  very  small 
percentage  of  alkalies,  to  tho,  impure  grey,  red,  or 
brown  clays,  containing,  along  with  alumina  and  sil- 
ica, magnesia,  potash,  soda,  iron,  lime,  and  carbon. 
Kaolin  is  used  with  China  stone  (a  combination  of 
felspar  and  quartz)  to  make  porcelain,  the  finest  and 
hardest  paste  known  .to  potters.  It  has  a  very  hard 
white  translucent  body,  only  slightly  vitreous  at 
the  highest  fire  (around  1700\°  Centigrade). 

From  this,  the  highest  grade,  we  have  almost  in- 
sensible gradations  to  common  earthenware.  Old 
English  and  French  porcelain  were  compounded  of 
clay,  sand,  and  alkalies  ground  together  to  make  a 
frit,  re-ground  and  mixed  with  a  stiffening  material 
(in  English  porcelain,  bone-ash),  to  support  the 
vitreous  matter  in  the  intense  heat.  The  finest 
earthenware  does  not  differ  greatly  in  its  formula 
from  soft  porcelain,  but  it  is  not  so  hard  or  trans- 
parent. From  this  the  scale  descends  to  where  the 
presence  of  lime  or  iron  in  the  body  colour  it  and 
render  it  easily  fusible,  so  that  at  any  great  heat  it 
turns  black  and  collapses  to  a  slag. 

Clay  on  being  dug  up  is  usually  weathered  in  the 
open,  and  dried  and  broken  up  and  the  greater 
impurities  picked  out.  It  is  then  thoroughly  mixed 


21 

with  water  in  a  blunger  and  passed  through  a  suc- 
cession of  sieves  until  all  foreign  matter  and  impuri- 
ties are  left  behind  and  it  is  the  consistency  of  cream. 
This  was  formerly  done  by  hand,  the  clay  being  raked 
into  a  thick  "slub"  and  washed  through  a  series  of 
tanks  until  all  impurities  had  settled,  leaving  only  the 
fine  clay  in  suspension.  It  is  at  this  stage  that  any 
additions  are  made  to  form  a  paste.  The  modifying 
ingredients,  ground  and  sieved  to  the  requisite  degree, 
are  thoroughly  incorporated  with  the  slip,  which  is 
allowed  to  settle.  The  clear  water  on  top  is 
siphoned  off  and  the  paste  dried  sufficiently  to  handle. 
The  modern  method  of  preparation  is  to  force  the 
slip  through  a  series  of  straining  bags  which  remove 
most  of  the  water  and  leave  it  stiff  enough  to  work. 
Some  of  the  hard  pastes  are  so  stiff  or  short  that 
they  require  soap  water  to  give  plasticity,  but  usually 
after  a  thorough  wedging  it  is  now  ready  for  the 
thrower. 

Generally  speaking,  kaolin,  China  clay,  ball  clay, 
pipe  clay,  China  stone,  felspar,  flint,  quartz,  sand, 
lime,  chalk,  and  calcined  bone  are  the  ingredients 
of  most  modern  pastes.  These  supply  the  alumina, 
silica,  lime,  potash,  and  soda,  with  traces  of  iron  and 
magnesia,  that  are  found  in  all  clays  when  analyzed. 
Carbon  is  only  present  in  impure  bodies  fired  at  a 
low  heat. 

Of  these  materials  the  clays  rich  in  alumina  and 


silica,  such  as  kaolin  or  China  clay,  form  the  body- 
giving  substance.  The  felspar  or  China  stone 
furnish  the  fluxing  ingredients  for  fusing  and  bind- 
ing. The  flint  or  bone  supplies  the  stiffening  matter 
for  supporting  and  retaining  the  shape  of  the  object 
in  the  fire. 

Porcelain,  though  differing  so  widely  in  appear- 
ance and  texture  from  the  coarse  mediaeval  earthen- 
ware or  the  pottery  of  the  ancients,  is  found  to  have 
a  distinct  relationship  when  all  these  bodies  are 
submitted  to  analysis.  Much  of  the  difference  in 
bodies,  apart  from  the  impurities,  lies  in  the  tem- 
perature of  the  fire  to  which  it  has  been  submitted. 
At  a  low  temperature  such  constituents  as  lime  and 
iron  are  not  much  affected,  but  at  a  greater  heat 
they  act  as  fluxing  agents. 

To  generalize  upon  a  complex  and  difficult  subject 
one  might  say  that  porcelain,  both  hard  and  soft 
(pate  dure  and  pate  tendre),  is  characterized  by  its 
pure  white  colour  and  by  extreme  hardness  of  body 
and  glaze  with  transparency;  fine  stoneware  by 
a  very  hard,  opaque,  and  heavy  body  which  may 
be  white,  buff,  or  grey,  and  salt-glazed  or  with  a  fine 
hard  transparent  glaze.  Earthenware  is  softer  and 
mostly  opaque.  It  may  range  from  something  a 
little  softer  than  soft  porcelain  to  the  coarse  "Ma- 
jolica" with  a  tin  glaze,  differing  widely  in  colour 
of  body  and  hardness  of  glaze. 


23 

With  porcelain  and  the  finest  high-fired  wares 
a  purity  of  materials  and  uniformity  of  mass  is  abso- 
lutely necessary.  It  is  here  that  one  may  well  call 
in  the  aid  of  the  chemist  and  manufacturer.  In 
any  case  it  is  advisable  to  call  in  the  chemist  and  the 
manufacturer  when  working  on  a  large  scale.  With 
a  small  output,  as  with  all  good  craftsmen,  the  fab- 
rication of  a  good,  reliable  stoneware  or  earthenware 
paste  is  only  a  matter  of  patience  and  hard  work. 
Before  commencing  to  produce  finished  work  on  any 
scale,  repeated  experiments  with  different  clays  should 
be  carried  out.  Notes  of  all  trials,  with  and  without 
glaze,  are  invaluable  to  the  potter. 

Rich  clays  can  be  stiffened,  short  clays  enriched, 
and  colour  modified  without  a  mass  of  expensive 
machinery.  Rich,  easily  fusible  clays  tend  to  stunt 
or  buckle  at  a  high  fire.  Hard  refractory  clays  often 
remain  porous  and  are  a  fruitful  source  of  crazing 
and  breaking.  The  addition  of  flint  or  fine  washed 
sand,  finely  powdered  grog,  or  pitchers,  or  even  re- 
fractory China  clays,  in  quantities  varying  from 
about  5  per  cent  to  20  per  cent,  but  settled  only  by 
repeated  trials,  will  stiffen  up  or  open  out  rich  clays 
inclined  to  warp  or  burst.  Rich  fusible  clays  added 
to  hard  clays  may  stop  the  crazing,  or  the  fusing 
point  may  be  lowered  by  the  addition  of  spar.  Stiff 
gravelly  clay  will  require  finer  sieving  or  repeated 
washing  to  rid  it  of  some  of  the  grit  or  sand.  Rich 


24 

greasy  clays  are  better  when  not  too  finely  sieved,  but 
this  point  is  of  course  dependent  on  the  class  of  work 
to  be  undertaken.  Slip  can  be  settled  in  tubs,  the 
water  siphoned  off,  and  then  put  to  dry  on  plaster 
bats,  or  dry  clay,  powdered  and  sieved,  may  be 
stirred  in  until  the  mass  is  stiff  enough  to  wedge 
thoroughly  by  hand. 

In  mixing  or  modifying  without  machinery  it  is 
sometimes  advisable  to  do  it  in  the  dry  state,  other- 
wise some  of  the  heavier  materials  are  likely  to  sink 
and  are  thus  not  thoroughly  incorporated  with  the 
body.  The  dry  mass  when  well  mixed  is  wetted 
enough  to  be  wedged.  When  the  body  is  coloured 
and  a  white  ground  is  indispensable,  an  "engobe," 
or  dip,  of  white  clay  slip  must  be  resorted  to. 

These  processes  are  certainly  tedious,  but  that  will 
not  deter  a  craftsman  searching  for  the  right  clay 
in  which  best  to  shape  his  ideas.  To  the  craftsman 
working  alone  it  is  the  only  way  by  which  he  can 
accommodate  his  clays  to  the  various  necessities  of 
throwing,  casting,  or  modelling.  Each  process  will 
require  a  slightly  different  nature  in  the  clay  if  the 
finest  results  are  to  be  obtained. 

Although  in  this  craft-book  we  shall  not  approach 
porcelain,  a  good,  hard,  true-ringing  body  with  a  tough 
well-fitting  glaze  should  be  a  sine  qua  non  with  all 
craftsmen ;  and  it  is  only  in  the  fire  that  any  true 
idea  can  be  gained  of  the  important  influences  clays 


25 

and  pastes  have  on  the  finished  work.  Here  we  have 
tried  to  indicate  the  chief  characteristics  of  clays  and 
to  make  clear  the  inevitable  tendency  of  all  potters 
who  seek  an  imperishable  medium  for  their  craft 
towards  a  purer  body  and  a  higher  fire. 


CHAPTER  HI 

BUILT  SHAPES 

"Every  moment  think  steadily :  to  do  what  thou  hast  in 
hand  with  perfect  and  simple  dignity." 

—  M.  ANTONINUS. 

WITH  good  plastic  clay  and  with  the  aid  of  a  few 
simple  tools,  the  fingers  can  fashion  shapes  of  con- 
siderable diversity  and  some  refinement.  In  ele- 
mentary schools  this  is  by  far  the  best  method  of 
teaching  the  beginner.  In  any  case  the  student  who 
has  no  knowledge  of  clay  work  would  do  well  to  start 
by  building  a  few  shapes  in  the  manner  still  used  by 
primitive  peoples. 

The  clay,  which  must  be  in  good  condition  and  not 
short,  is  rolled  out  on  a  wet  plaster  slab  or  some  non- 
sticky  surface,  into  ropes  of  something  less  than  half 
an  inch  in  diameter  for  small  shapes.  (Fig.  1.)  The  best 
way  to  commence  is  to  knead  up  a  double  handful 
of  soft  clay  until  thoroughly  mixed,  ball  it,  and. then 
form  a  stumpy  cylinder,  gradually  elongating  by 
rolling  out  on  the  bat.  Too  much  pressure  will 
flatten  the  rope  and  there  should  be  a  distinct  pull 

26 


ROLLING  OUT  CLAY 


FIG.  1 

or  stretch  on  it  in  addition  to  the  downward  pressure, 
varying  as  necessary  to  insure  even  thickness.  As 
the  rope  becomes  thinner  the  fingers  should  be  held 
diagonally  to  avoid  ridges.  This  rope  should  be 
fairly  firm  and  yet  bend  easily  without  cracking. 
With  a  little  practice,  long  pliable  rolls  can  be  easily 
and  rapidly  produced  and  then  a  start  is  made  with 
the  base.  This  is  coiled  as  in  Fig.  2,  pressed  flat,  and 
welded  together.  It  is  finished  both  sides  before 
commencing  the  walls  of  the  shape.  These  are 
coiled  round  and  up,  each  ring  being  pressed  firmly 
on  the  one  below,  care  being  taken  to  avoid  air 
cavities  which  may  blow  out  on  firing.  The  top  is 
levelled  off  and  the  sides  welded  together  and 
smoothed  with  the  fingers.  (Fig.  3.) 

At  first,  simple  and  almost  straight-sided  shapes 


FORMING  COIL 
FOOA/E 


FIG.  2 

should  be  attempted ;  each  ring  may  be  added  sepa- 
rately, while  the  finishing  should  not  be  unduly  pro- 
longed. As  the  technique  improves,  curves  with 
slight  returns  may  be  attained.  Where  the  size 
is  so  great  as  to  prevent  finishing  at  one  sitting,  it 
can  be  very  carefully  reversed;  this  will  allow  the 
base  to  harden  and  still  keep  the  top  moist  for  further 


WELDING 
/MOOTHINC 
THE  /JDEy. 


FIG.  3 


coiling.  With  big  pieces  much  attention  must  be 
paid  to  the  correct  shaping  when  coiling,  otherwise 
the  finishing  will  be  laborious  and  quite  possibly 
useless.  Large  shapes  with  difficult  curves  are 
best  built  in  two  sections  or  parts  and  then  carefully 
welded  together.  To  keep  the  parts  damp  during 
prolonged  operations,  use  water  blown  from  a  spray 
diffuser. 


30 

Ash  trays,  bulb  bowls,  flower  pots,  salt  cellars,  and 
ink  wells  are  a  few  of  the  things  that  are  suitable 
to  be  made  by  this  method.  They  may  be  decorated 
with  incised  lines,  raised-ornament  handles,  and  feet. 
Additional  interest  is  obtained  by  slight  banding,  or 
the  incised  lines  filled  in  with  a  coloured  clay  pressed 
firmly  in  when  the  shape  is  tough.  Although  built 
forms  may  be  quite  highly  finished,  it  is  obvious  that 
any  elaborate  decoration  is  out  of  place  on  shapes 
that  by  their  origin  must  be  simple  and  somewhat 
heavy.  Enough  has  been  said  to  indicate  the 
process.  For  its  logical  development  and  suitable 
enrichment  we  must  study  the  work  of  primitive 
peoples.  For  its  possibilities  we  must  turn  to  the 
vast  jars  made  even  to  this  day  in  Spain. 

With  great  care  and  much  taste  pieces  can  be 
pinched  and  welded  together  into  delightful  forms, 
best  shown  in  the  refinements  of  the  Cha  Noya 
pottery  of  Japan.  This  pinching  must  be  done 
carefully  and  above  all  sympathetically.  To  those 
that  know  or  feel  the  possibilities  of  the  clay  it  will 
respond  readily.  Much  more  taste  and  judgement  is 
required  in  the  making  of  a  really  satisfactory  pinched 
shape,  than  is  needed  in  forming  one  with  coils. 
Square,  polyhedral,  or  irregular  shapes  other  than 
circular  may  be  stuck  up  or  pieced  together  in  the 
following  manner :  Upon  a  table  nail  two  strips  of 
wood  one  quarter  of  an  inch  thick,  ten  or  twelve 


31 


ATTACHING 


FIG.  4 

inches  apart.  Sprinkle  between  the  strips  with  flint 
or  fine  sand  and  batter  out  some  soft  clay  thereon. 
Scrape  the  surplus  clay  off  with  a  straight-edge  and 
then  roll  the  clay  between  the  strips  flat  with  a  roll- 
ing pin.  Upon  this  thin  slab  mark  out  the  sides,  base, 
top,  etc.,  of  the  shape  to  be  built.  Run  a  thin  knife 
round  each  shape,  but  do  not  cut  quite  down  to  the 
table.  Cut  along  the  inside  edge  of  each  strip  to 
allow  the  whole  slab  to  contract  evenly  and  allow 
it  to  toughen  slightly.  Carefully  remove  and  reverse 
the  slab  and  separate  the  pieces,  being  careful  not 
to  distort  the  shapes  in  the  process. 


u 


'STICKING  q?? 


FIG.  5 

The  shape  must  be  stuck  up  before  the  pieces 
become  brittle  or  too  stiff  to  bend.  Roughen  each 
opposing  edge  and  moisten  with  slip,  that  is,  clay 
mixed  with  water  to  the  consistency  of  thick  cream. 

Press  the  edges  firmly  together  and  weld  well  each 
joint  with  soft  clay.  (Fig.  5.)  This  operation  should 
be  most  thorough,  as  any  weak  joint  will  inevitably 
open  when  fired.  Lids  should  be  cut  slightly  larger 


33 


than  the  shapes  they  have  to  fit  and  sandpapered 
true  when  dry.  Sharp  edges  and  angles  should  be 
smoothed  with  the  fingers  before  the  shape  gets  hard. 

The  chief  pitfall  to  avoid  in  this  process  is  a  hard 
wooden  look.  The  ductile  plastic  qualities  of  the 
clay  should  be  remembered  and  such  additions  as 
feet  or  handles  should  emphasize  this  important 
point. 

Finally,  the  careful  sympathetic  craftsman,  with 
infinite  patience,  by  utilizing  all  three  methods, 
can  build  vessels  of  almost  any  shape,  —  square, 
round,  elliptical,  banded,  strapped,  bossed,  fluted, 
and  embellished  with  handles,  spouts,  and  feet. 
Ancient  and  mediaeval  pottery  is  rich  in  such 
forms. 


aXTTINGEDCE 


(s 


WILE 


TOOLS  FOR  CLAY  WOEJC 


CHAPTER  IV 
MOULDING,  CASTING,  AND  PRESSING 

"Our  soundes  is  good,  Our  shapes  is  neat, 
Its  Davis  cast  us  so  compleat." 

—  From  an  old  bell  at  Stoke  Rivers. 

THE  casting  process,  employed  so  extensively  in 
commercial  work,  is  in  its  essence  mechanical  and 
therefore  can  never  have  the  spontaneity  or  char- 
acter of  thrown  work.  To-day  when  the  thrower 


r;* 


MANDREL, 

ROlLIDlNPAPnU- 


FIG.  6 

and  turner  with  hand  and  eye  trained  for  good  shapes 
is  rare  indeed,  it  is  often  the  only  method  by  which 
the  student  can  obtain  large  shapes  of  high  finish 
for  painting  or  glazing  in  transparent  colours. 
In  the  process  the  shape  is  first  designed  and 

34 


35 


EDGE. 


'ONETIECl'MOVLD  IOK- 
JOWL-  METHOD  OF 
MLEASINC  ORIGINAL 


FIG.  7 


carefully  drawn  on 
paper,  allowance  be- 
ing made  for  the 
shrinkage  of  the  fin- 
ished pot  which  may 
be  as  much  as  1  in 
6  with  some  kinds  of 
slip.  It  should  be 
refined  in  profile 
with  no  returns  that 
may  bind  or  hold  in 
the  mould  when  dry- 
ing, yet  it  is  obvious  that  simple  shapes  that  can  be 
built  or  thrown  by  the  beginner  are  not  suitable  for 

casting. 

The  shape  correctly 
drawn,  a  mandrel,  a  steel 
tapering  to  a  point  the  butt 
wormed  to  screw  on  a  lathe, 
and  long  enough  to  give  some 
play  at  either  end,  is  rolled 
in  stout  paper,  gummed  at 
the  edges,  as  in  Fig.  6. 
This  is  removed  and  allowed 
to  set,  thus  giving  a  paper 
shell  just  fitting  the  man- 
drel. Trim  this  square  at 
the  base  and  stick  it  upright 


ATWO-HECE 
MOULD. 


FIG.  8 


36 


POURING  IN  PLA/TER. 


PIG.  9 


37 

by  means  of  a  piece  of  clay  on  a  well-oiled  portion  of 
a  table.  Around  this  as  a  centre  is  fitted  a  roll  of 
linoleum,  oiled  inside  and  secured  with  string,  with  all 
its  joints  caulked  with  clay.  The  inside  diameter  of 
this  cylinder  should  be  about  \"  larger  than  the 
greatest  diameter  of  the  drawn  shape.  Enough 
superfine  plaster  to  fill  this  is  now  mixed.  To  do  this 
shake  plaster  by  handfuls  into  a  bowl  of  water  until 
it  appears  to  refuse  more,  pour  off  any  surplus  water, 
and  stir  with  a  wooden  ladle  or  the  hand,  avoiding 
air  bubbles. 

A  little  practice  in  casting  plaster  bats  will  give 
the  experience  necessary  for  mixing  plaster.  When 
well  mixed  and  a  slight  thickening  is  perceptible,  it 
is  poured  very  carefully  into  the  cylinder,  the  paper 
shell  being  kept  upright  in  the  centre.  (Fig.  9.)  In 
about  20  minutes  the  surface  of  the  plaster  will  feel 
warm.  It  is  now  set  and  the  linoleum  is  removed.  The 
plaster  cylinder,  when  dry,  is  fitted  on  the  mandrel,  and 
this  screwed  to  the  lathe  head.  Two  or  three  chisels 
are  now  required.  (Fig.  10.)  The  rest  on  the  lathe 
is  clamped  in  a  convenient  position  and  a  cutting 
chisel  held  as  shown  (Fig.  11),  cutting  edge  up.  The 
cylinder  is  revolved  briskly  as  indicated  by  arrow,  and 
the  shape  is  roughly  hollowed  out.  Proceed  gradually 
until  the  shape  begins  to  emerge,  taking  care  not 
to  cut  too  deeply.  (Fig.  12.)  Towards  the  finish  use 
the  calipers  frequently  to  check  the  measurements. 


38 


TqRNBsIQTOOL. 


CHISEL  POINTS 


At  top  and  bottom 
about  \"  waste  is  left 
(Fig.  13  A),  turned 
straight,  the  actual  line 
of  top  and  base  being 
slightly  grooved  in  the 
plaster.  The  form  may 

be  pretty  accurately  finished  with  the  chisels  and  then 
nicely  smoothed  with  sandpaper.  For  this  process 
the  rotary  movement  is  reversed. 


FIG.  10 


PO/ITION  Of  TOOL 


FIG.  11 


The  shape  is  now  removed  from  the  lathe  and  is 
ready  for  moulding. 

With  a  kick  wheel  having  a  removable  head  the 
mandrel  can  be  screwed  on  and  the  block  turned 


39 


PAKTLY  TCJltfsltD  JLOCK  ON  LATHI 


FIG.  12 

down  in  an  upright  position.  The  difficulty  of 
steadying  the  tool  renders  this  method  somewhat 
unsuitable  for  this  process,  where  perfect  sym- 
metry and  a  high  finish  are  required.  The  plaster 
should  not  be  so  dense  for  turning  on  the  wheel  or  the 
kicking  is  apt  to  become  very  arduous  and  this  tends 
to  dislocate  the  set  of  the  spindle.  One  of  the  best 
of  ways  is  to  draw  a  quantity  of  shapes,  cast  their 
blocks,  and  turn  them  on  a  hired  lathe,  preferably 
run  by  power. 

The  finished  shape  is  now  well  lathered  with  part- 
ing or  stopping.  This  is  made  by  boiling  1  Ib.  soft 
soap,  J  Ib.  Russian  tallow,  and  a  small  piece  of  soda. 
Another  stopping  is  made  by  dissolving  1  Ib.  soft 
soap  in  1  qt.  water  and  stirring  in  J  pt.  paraffin 
oil.  Several  coatings  may  be  necessary  to  impart 


40 

a  waxy  surface.  When  no  longer  absorbent,  it  is 
dried  and  slightly  polished  with  a  bit  of  cotton 
waste.  At  the  finish  the  form  should  be  clean, 
smooth,  glossy,  and  non-absorbent. 

With  simple  shapes,  as  in  Figs.  7  and  8,  a  one-piece 
or  a  two-piece  mould  can  be  made,  and  here  the  bot- 
tom waste  is  not  necessary,  but  with  any  return  or 
foot  a  three-piece  mould  will  be  required.  The  waxed 
shape  is  now  divided  perpendicularly  exactly  in  half, 
by  a  pencil  line.  (A,  Fig.  13.)  It  is  then  laid  on  its 
side  and  bedded  in  clay  up  to  the  pencil  lines,  the 
clay  being  sloped  slightly  down  from  the  marks.  (F, 
Fig.  13.)  Box  in  now  with  well-soaped  boards  tight 
against  top  and  bottom  but  allowing  about  l£"  at 
sides.  Wipe  the  shape  over  with  waste  dipped  in 
olive  oil  but  leave  no  surplus  oil  on  the  surface. 
Plaster  well  mixed  as  before  is  poured  in  until  about 
1 J"  to  2"  above  the  greatest  projection  of  the  shape, 
great  care  being  taken  to  avoid  or  dislodge  air 
bubbles.  (B,  Fig.  13.) 

When  the  plaster  is  set  but  still  warm,  the  shape  is 
removed  and  the  side  of  the  plaster  that  rested  on 
the  clay  trimmed  flat  and  several  joggles  or  natches 
are  made.  (C,  Fig.  13.)  The  shape  is  now  replaced 
exactly  as  cast  and  the  new  surfaces  treated  with 
parting  and  the  whole  slightly  filmed  with  oil  as 
before.  Great  care  must  be  used,  for  any  oil  on  the 
actual  surface  of  the  mould  spoils  the  suction  of  the 


41 


MOULDING  VT  HAL? 


MOULDING  i"1  HALT  MOULDING  2/40  HAL? 

i 


MOULDING  BA/E  ^     AMFTHOD 


D 


FIG.  13 


42 

plaster  at  that  spot.  Box  in  and  then  cast  just  as 
before.  This  gives  two  halves  with  waste  top  and 
bottom. 

The  shape  is  now  placed  on  the  lathe  and  the  bot- 
tom waste  turned  off,  the  base  of  the  shape  being 
slightly  hollowed.  The  creator  having  arrived  so 
far  successfully  may  now  unbend  and  scratch  his 
mark  on  this  new  surface  before  well  waxing  it. 

Dowels  are  cut  in  the  waste  of  the  two  halves  as 
shown,  the  fresh  parts  soaped,  all  fitted  together  and 
slightly  oiled,  then  boxed  in  as  in  D  and  E,  Fig.  13. 
Plaster  about  2"  thick  at  the  thinnest  part  is  poured 
on  and  the  mould  is  complete.  When  set,  the  shape 
is  removed  and  the  three  parts  trimmed  on  all  the 
outside  edges.  (Fig.  14.)  The  three  pieces  are  assem- 
bled, firmly  tied  up  to  prevent  warping,  and 
thoroughly  dried. 

If  preferred,  the  mould  can  be  made  cylindrical 
instead  of  square.  This  will  give  a  more  even  suc- 
tion to  the  slip  and  may  be  worth  the  extra  trouble. 
For  casting  purposes  a  refractory  clay  containing  a 
good  percentage  of  China  clay,  maturing  at  about 
03-01  but  remaining  perfectly  white  and  porous, 
will  be  required. 

Slip  for  casting  is  made  thus:  Clay,  picked  or 
broken  into  small  pieces,  is  thrown  into  a  bucket  of 
warm  water  well  slubbed  up  by  hand  and  passed 
through  a  fine  sieve  (No.  80)  with  the  aid  of  a  stout 


43 


THE  THREE  PART/ 
OFTHEMO^LD. 


FIG.  14 

brush  and  thinned  to  the  consistency  of  thick  cream. 
This  should  be  matured  for  some  days,  frequently 
stirred,  and  again  sieved  before  using.  For  very 
small  or  fragile  shapes,  a  finer  sieve  (120)  is  advisable. 
The  mould,  quite  dry  and  clean,  is  now  slightly 
moistened  with  a  scrupulously  clean  sponge  and 
water,  the  parts  assembled,  corded,  and  firmly 
wedged,  leaving  the  top  free  as  in  Fig.  15.  The  slip, 
thoroughly  stirred,  is  poured  in  very  gently  to  avoid 
bubbles.  With  awkward  moulds,  a  tube  or  funnel 
should  be  used  to  prevent  splashing.  If  the  mould 
be  placed  on  a  whirler  and  turned  to  and  fro,  it  will 
prevent  the  heavier  matter  in  the  slip  settling  too 
quickly. 


44 


As  the  slip  sinks  in  the  mould,  the  subsidence 

being  due  to  the  ab- 
sorption of  the  water 
by  the  plaster,  the 
mould  should  be  con- 
tinually filled  up. 
After  a  few  minutes 
the  mouth  is  scraped 
free  to  test  the  de- 
posit. When  this  is 
thick  enough,  vary- 
ing, of  course,  with 
the  size  of  the  shape, 
MOCILD  READY  TOR  /LI  P  -  tne  sliP is  poured  out 


FIG.  15 


into  another  bucket. 

An  unorthodox  but 
often  useful  trick  for  strengthening  long  necks  is 
to  slide  a  piece  of  glass  over 
the  mouth  and  reverse  the 
mould  for  a  minute  or  so. 
The  neck  full  of  slip  thus 
allows  a  slight  extra  deposit 
on  the  part  that  most  needs 
it  when  we  come  to  finishing 
off  the  lip. 

Let  the  mould  drain  a 
little  over  the  slip  bucket 
and  then  reverse  to  dry  FIG.  16 


FBEHMGTOP 


45 


slowly.  When  the  wet  look  has  disappeared  from 
the  surface  of  the  slip,  scrape  the  top  free  and  run  a 
knife  around  to  prevent  sticking  as  the  shape  con- 
tracts. (Fig.  16.)  In  a  few 
hours  it  will  be  dry  enough 
to  permit  of  the  sides  being 
eased  off  and  the  shape  left 
to  dry  on  the  base.  (Fig.  17.) 
When  tough  enough  to 
handle  with  safety,  the  waste 
and  cast  lines  are  trimmed 
and  finished  off,  any  air 
bubbles  or  holes  broken 
down  and  filled  with  clay 
scraped  from  the  waste  or 
base.  If  this  finishing  is  left 
until  the  shape  be  dry,  it 
is  impossible  to  hide  such 
defects.  The  greatest  care 
must  be  exercised  in  hand- 
ling cast  shapes,  as  they  are  I  ./H  APE  Kf  ADY 
exceptionally  fragile.  J  f  OKTRIMM1NC 

When  quite  dry,  the  whole 
form  should  be  carefully 
gone  over  with  a  very  fine  sandpaper.  A  superfine 
surface  should  be  imparted  by  rubbing  with  the 
hands.  When  using  transparent  glazes,  as  with 
under-glaze  painting,  it  is  essential  that  all  scratches 


FIG.  17 


46 

be  removed,  and  especially  must  all  sharp  edges 
be  eliminated  on  neck  or  shoulder,  for  the  glaze 
running  away  from  these  places  imparts  a  hide- 
ously cheap  look  to  what  otherwise  may  be  a  fine 
shape.  All  these  points  having  received  attention, 
the  date  is  scratched  on  the  bottom  of  the  shape  and 
it  is  now  ready  to  biscuit. 

Generally  speaking,  it  will  be  found  that  slip  the 
consistency  of  cream  is  right  for  casting,  possibly 
thicker  for  big  open  shapes,  and  after  the  right  pro- 
portion is  settled  it  is  as  well  to  test  what  it  weighs 
to  the  pint. 

As  will  be  readily  seen,  this  process,  whilst  open  to 
many  objections,  lends  itself  to  shapes  that  are  re- 
fined and  delicate  and  to  those  that  have  flutings  or 
raised  ornament.  Such  decorations,  or  the  spouts 
of  jugs,  may  be  modelled  in  wax  on  the  plaster  shape 
before  casting  and  appear  in  reverse  on  the  mould. 
Designs  may  be  scratched  on  the  mould  or  shape 
and  show  as  a  delicate  tracery  beneath  the  glaze. 
All  these  things,  however,  add  to  the  difficulty  of 
casting  and  should  be  approached  by  degrees  and 
with  restraint.  For  in  unskilled  hands  the  process 
lends  itself  to  soulless  and  mechanical  repetition. 

PRESSING 

Moulds  having  moderately  wide  mouths  enable 
the  potter  to  press  his  shapes  instead  of  cast  them. 


47 

This  method  in  expert  hands  is  even  quicker  than 
casting  and  has  the  advantage  of  imparting  a  sturdier 
look  to  large  shapes.  Pressing  is  also  resorted  to  for 
those  shapes  to  which  it  would  be  difficult  for  the 
slip  to  obtain  free  access. 

For  the  ordinary  three-piece  mould  the  procedure 
would  be  thus :    The  clay,  well  wedged  and  quite 


ROLLING 


OUT  CLAY 


FIG.  18 

plastic,  is  rolled  out  as  described  in  Jigger  and  Jolley 
work,  to  a  suitable  thickness.  (Fig.  18.)  Butter  cloth 
or  fine  linen  will  do  instead  of  leather  to  roll  the  clay 
on.  The  insides  of  the  three  parts  of  the  mould  are 
sponged  and  pieces  of  the  thin  rolled  clay  roughly 
cut  to  fit  them.  These  pieces  are  now  fitted  and 
well  applied  to  the  three  parts  by  dabbing  with  the 
damp  sponge.  A  soft  close-textured  sponge,  or  a 
soft  felt  dabber,  is  best  for  this  operation.  When 


48 

closely  setting,  the  edges  are  trimmed  and  given  a 
slight  bevel.  The  top  is  cut  straight.  Then  the 
mould  is  assembled  and  firmly  tied.  Some  of  the 
waste  clay  is  rolled  into  thin  ropes.  With  the  bev- 
elled edges  slightly  moistened,  these  ropes  are  firmly 
wedged  into  the  two  side  junctions  and  round  the 
base.  Where  the  mouth  is  large  enough  for  the  in- 
sertion of  the  hand  this  is  not  a  difficult  operation. 
If  it  be  narrow,  the  two  halves  of  the  mould  may  be 
tied  up  and  the  joints  welded  together  before  they 
are  assembled  on  the  base.  A  coil  of  clay  can  then 
be  placed  on  the  edge  of  the  base  just  clear  of  the 
two  sides  which  are  now  fitted  over  and  tied  up. 
Then  a  stick  sponge  is  used  to  join  up  the  base  to 
the  sides.  (Fig.  19.)  After  a  little  while  the  shape 
is  fit  to  be  removed  and  is  finished  in  the  usual  way. 

Nothing  can  rival  large  thrown  shapes  for  vigour 
or  variety,  but  unfortunately  they  are  not  always 
within  reach  of  even  the  good  craftsman.  Then 
this  method  offers  the  least  objectionable  substitute 
for  them  and  in  clever  hands  is  capable  of  many  fine 
results. 

The  following  method  is  used  to  mould  handles  or 
simple  applied  ornament.  Handles,  feet,  masks, 
etc.,  are  usually  pressed  and  stuck  on  the  dry  shape 
with  slip.  To  mould  them  some  skill  is  necessary 
if  the  press  is  to  be  quite  accurate  and  free  from 
twist  or  ugly  seams. 


49 


STICK-SPONGE 
WELPING  BAStTt>5ttMcS. 


FIG.  19 

One  way,  when  the  handle  or  foot  is  symmetrical, 
is  to  cut  the  model  exactly  in  half.  This  must  be 
done  when  the  model  is  tough  enough  to  handle  with- 
out bending  or  distorting  it.  One  half  is  laid  cut 
side  down  upon  a  sheet  of  glass,  and  surrounded 
at  a  convenient  distance  with  clay  walls.  Plaster 


50 


HALF  Of  MoqLp 
HANDLE 


FIG.  20 


is  now  poured  on  to  form  one  half  of  the  mould,  and 
allowed  to  set.  It  is  then  removed  and  the  smooth 
surface  joggled  and  clay  washed  (brushed  over  with 

claywater).  The 
other  half  is  then 
very  carefully  ap- 
plied to  the  half  still 
embedded  in  the 
mould,  the  walls  built 
round  and  the  other 
part  of  the  mould 
cast.  Then  all  is 
trimmed  up  and  a 
groove  run  round  the 
form  as  shown.  (Fig.  20.)  For  pressing,  the  form 
is  well  filled  with  clay  and  the  two  halves  of  the  mould 
strongly  pressed  together.  Any  surplus  clay  will 
squeeze  into  the  groove  and  when  tough  enough  to 
remove  the  whole  is  "fettled"  and  finished  before 
drying  and  sticking  up. 

With  care  and  practice  this  method  is  possible: 
Build  walls  and  pour  in  enough  plaster  to  form  one 
half  of  the  mould.  Before  it  stiffens,  very  carefully 
press  in  the  handle  or  ornament  just  up  to  the  half- 
way line  and  allow  to  set.  Joggle,  claywash,  and 
cast  the  second  half.  Finally,  when  the  object  is 
of  any  size,  clay  walls  may  be  used  as  described  in  the 
chapter  on  Figurines. 


CHAPTER  V 

JIGGER  AND  JOLLEY  WORK 

"Earth  I  am,  et  is  most  trwe,  desdan  me  not,  for  so  ar  you." 

—  From  an  old  platter. 

DISHES,  platters,  and  to  some  extent  bowls,  are 
usually  made  on  a  Jigger  and  Jolley.  The  jigger 
has  a  revolving  head,  fitted  to  receive  moulds.  The 
jolley  has  a  pivoted  arm  to  which  different  profiles 
may  be  clamped.  In  factories  these  things  are  com- 
plicated and  go  by  power,  but  in  a  studio  where  the 
output  of  platters  and  dishes  is  likely  to  be  limited 
something  simple  will  do.  Where  the  wheel  is 
'strong,  well-hung,  and  fitted  with  a  removable 
head,  a  contrivance  as  shown  at  Fig.  21  can  be  fitted 
by  any  carpenter,  that  should  serve  all  purposes. 

The  vertical  supports  of  the  jolley  arm  should  be 
quite  rigid.  The  arm  itself  must  so  pivot  that  the 
face  of  any  profile  screwed  onto  it  will  cross  the  head 
of  the  jigger,  or  wheel  if  one  be  used,  through  the 
centre.  In  other  words,  the  cutting  profile  must 
form  a  diagonal  of  the  circular  head.  Then,  too, 
it  must  be  hung  at. a  height  sufficient  to  allow  a 
fairly  thick  block  of  plaster  being  used  for  a  mould. 

When  making  these  moulds,   the  slotted   wheel 

51 


•MAKING  A DI/H 


FIG.  21 

head  or  the  jigger  head  is  removed  and  soaped  or 
oiled.  Then  a  circular  block  of  plaster  is  cast  to 
fit.  This  may  be  done  with  the  aid  of  a  roll  of  lin- 
oleum, much  in  the  way  described  in  casting.  The 
paper  cone  will,  of  course,  be  replaced  by  the  wheel 
head,  bedded  face  up  in  clay.  This  plaster  block  has 
to  be  moulded  to  the  exact  size  of  the  dish  or  plaque 
required.  To  do  this  a  profile  of  zinc  is  necessary. 
The  true  section  of  the  dish  is  drawn  full  size,  and 
profiles  giving  one  half  of  the  back  and  front  are 
traced  on  a  stout  sheet  of  zinc.  The  zinc  is  roughly 
cut  to  shape  with  shears  and  then  finished  with  a 
file  to  a  chisel  edge  (see  cut).  The  two  profiles  are 
then  firmly  backed  with  shaped  wooden  forms, 
slotted  to  screw  onto  the  arm  of  the  jolley.  The 


PROFILE  IN 
P-Q/1T10N 
ABC3W 
PLATE  MOMCD 


FIG.  22 

profile  giving  the  /ace  of  the  plaque  is  securely  ad- 
justed in  a  horizontal  position,  the  inner  point, 
giving  the  centre  of  the  platter,  being  exactly  over 
the  centre  of  the  jigger  head.  The  plaster  block, 
which  should  be  turned  down  before  it  sets  hard,  is 
shipped  back  into  position,  the  jigger  revolved  and 
the  profile  gradually  pressed  down  until  the  true 
section  is  obtained,  i.e.  when  the  profile  is  exactly 
horizontal  again.  The  mould  is  now  removed, 
trimmed  at  the  sides  if  necessary,  and  set  apart  to 
dry.  It  is  then  ready  to  use.  The  mould  is  slipped 
into  position  and  revolved  to  insure  even  rotation. 
Then  the  profile  giving  the  back  of  the  platter  screwed 
onto  the  arm  and  both  adjusted  until  the  stop 
allows  the  profile  to  rest  at  just  that  distance  from 
the  mould  required  by  the  thickness  of  the  platter. 
(Fig.  22.) 


54 


The  arm  is  then  swung  clear  of  the  mould,  which 
is  well  sponged  with  water  to  receive  the  clay.  This 
is  carefully  wedged  and  then  rolled  out  or  batted  flat 
on  a  piece  of  leather  until  it  is  a  little  thicker  than 

the  thickest  part  of  the 
platter  (see  Fig.  23).  The 
slab  so  made  is  smoothed 
with  a  palette  knife,  taken 
up,  leather  and  all,  slapped 
onto  the  mould,  clay  side 
down,  and  the  leather  re- 
moved. The  clay  is  now 
well  dabbed  down  with  a  wet 
sponge  or  dabber,  to  take 
out  all  wrinkles,  pressed 
firmly  onto  the  mould  and 
the  waste  cut  off. 
Now  the  jigger  or  head  is  set  spinning,  the  jolley 
pulled  over  it,  and  the  profile  gently  pressed  into  the 
clay.  Water  is  used  freely  to  prevent  the  profile 
sticking,  and  as  it  becomes  clogged  the  clay  is 
removed.  The  turning  is  continued  until  the  profile 
comes  to  a  stop  on  the  rest.  Holes  that  may  appear 
should  be  filled  up  before  the  finish,  at  which  time  the 
surface  should  present  a  smooth  unscratched  appear- 
ance. The  shape  is  allowed  to  dry  on  the  mould  until 
tough  enough  to  be  slipped  face  down  onto  a  per- 
fectly flat  slab  dusted  with  fine  sand  or  flint  to  pre- 


CUTTINGEDCE 
OFPKOEiLE 


FIG.  28 


55 


vent  sticking.     In  this  position  it  is  left  to  dry,  when 
the  edges  are  nicely  trimmed  with  fine  sandpaper. 

For  bowls  the  process  is  similar,  but  the  mould 
here  gives  the  outside  and  the  profile  the  inside  as 
in  cut.  (Fig.  24.)  If  made 
on  the  outside,  they  split 
before  they  can  be  removed. 
With  small  bowls  the  clay  is 
wedged  and  a  lump  pressed 
into  the  mould  by  hand. 
With  large  bowls  requiring 
a  deep  foot  this  must  be 
turned  separately  and  stuck 
on  after  the  bowl  is  removed 
from  the  mould. 

Where  a  jigger  and  jolley 
is  not  available,  plates  and 
bowls  may  be  duplicated  as 
follows :  Place  the  plate  bottom  up  on  a  well-soaped 
surface  or  a  piece  of  glass.  Should  the  plate  not  lie 
quite  flat,  caulk  the  apertures  with  clay,  then  all  round 
and  distant  one  and  one  half  inches  from  the  rim, 
build  clay  walls,  or  fix  a  containing  band  of  linoleum, 
of  sufficient  height  to  allow  plaster  being  poured  in  an 
inch  and  a  half  above  the  base  or  foot  of  the  model. 
Mix  fairly  stiff  plaster  and  pour  in.  Let  it  set,  and 
then  remove  walls  and  the  model.  This  gives  a  mould 
of  the  reverse  of  the  plate  or  bowl.  The  mould  is 


BOWL 


FIG.  24 


56 


PLATE  -MOULDIP 
TO  GIVE  BACK- 


Fio.  25 

thoroughly  dried  before  using  and  then  sponged 
with  clean  water.  Clay  of  the  desired  thickness 
is  then  rolled  out  as  described  and  applied  to  the 
mould  and  dabbed  flat  with  a  sponge  or  dabber. 
The  finish  is  imparted  with  the  fingers  and  the 
surplus  at  edges  trimmed  with  a  knife.  When 


PLASTER     MOULP.  To  GIVE 
te^&a^.       TACt  or  PLATE. 


.&OWJ3 


FIG.  26 

tough,  the  press  is  slipped  out  and  reversed  to  dry 
on  a  piece  of  sanded  glass.  Where  there  is  a  rim 
to  the  plate  or  bowl,  this  should  be  filled  in  cleanly 
with  clay  before  the  whole  is  pressed.  It  is  of  course 
impossible  to  mould  thus  bowls  that  possess  a 
deep  or  undercut  foot. 


58 


E^ypt.     B.<?.  2000 


CHAPTER  VI 

THROWN  SHAPES 

"The  lyf  so  short,  the  craft  so  longe  to  learne." 

—  CHAUCER. 

THE  wheel  is  the  true  fountain  head  of  all  beautiful 
shapes,  and  the  student  who  would  become  a  potter 
cannot  get  "on  the  wheel"  too  soon.  Throwing, 
sometimes  spinning,  is  the  term  applied  to  the  mak- 
ing of  shapes  on  the  wheel.  Interesting  and  really 
fine  pots  may  be  built  or  cast,  but  the  ultimate  appeal 
rests  with  the  thrown  shape. 

Unfortunately,  a  complete  mastery  of  throwing 
is  not  to  be  gained  by  a  few  spasmodic  wrestles  with 
the  wheel.  It  comes  only  with  long  hours  of  con- 
centrated effort.  Having  watched  an  accomplished 

59 


60 

thrower  and  seen  the  full  round  shapes  rise  so  easily 
between  his  dexterous  fingers,  it  is  with  a  severe 
shock  that  one  realizes  at  the  first  attempt  the  skill 
and  practice  that  will  be  required  before  such  a 
desirable  proficiency  is  attained. 

The  best  kind  of  wheel  is  the  kick  wheel  shown 
in  the  illustration.  With  this  the  feet,  hands,  and 
head  work  in  harmony,  accelerating  or  retarding 
the  motions  as  required.  It  is  a  not  distant  rela- 
tion of  the  earliest  wheel,  which  was  a  heavy  head 
on  a  short  shaft,  pivoted  in  a  stone  socket.  Set 
spinning  by  hand,  it  was  kept  revolving  some  time 
by  its  own  momentum.  This  form  of  wheel  is  used 
even  to  this  day  in  the  near  and  far  East. 

Its  first  development  was  a  secondary  wheel  and 
driving  band  turned  by  hand.  This  led  to  the  wheel 
shown  in  the  frontispiece  and  to  the  kick  wheel  and 
again  on  to  the  factory  wheel.  This  in  its  turn  is 
being  superseded  by  the  steam  wheel,  which  gears 
onto  a  running  band,  the  foot  being  used  to  start, 
stop,  and  regulate  the  speed.  The  two  last  named 
were  introduced  with  the  idea  of  accelerating  the 
production  rather  than  the  improvement  of  the 
shapes.  No  doubt  the  now  primitive  kick  wheel, 
much  as  used  by  the  potters  of  the  Renaissance, 
will  be  found  good  enough  for  us. 

The  tools  required  for  throwing,  after  the  wheel 
itself  is  secured,  are  as  follows :  a  thin  copper  wire 


61 


THROWING^  f  tWINGTOOL/ 


FIG.  27.     1,  "Rib"  ;   2,  Modelling  Tools  ;   3,  Pricker;   4,  Sponge; 
5,  Wire;  6,  7,  and  8,  Shaving  Tools;  9,  Leather. 

twisted  between  two  bits  of  wood,  a  pricker,  a 
fine  soft  sponge,  another  bit  of  sponge  tied  to  a 
stick,  one  or  two  modelling  tools  and  a  rib  (see 
Fig.  27). 

The  clay  is  first  knocked  up  into  shape  ready  for 
the  throwing.  To  do  this  it  is  wedged,  a  fair-sized 
piece  being  taken  in  both  hands  and  thrown  vio- 
lently down  on  the  bench,  cut  across,  and  smashed 
together  again.  This  process  is  repeated  until 
all  air  bubbles  are  expelled.  This  is  ascertained 
by  cutting  with  a  wire.  The  finger  is  then  passed 
across  the  surface  to  tell  if  it  is  well  together,  and 


62 

not  hard  and  soft  in  streaks.  If,  as  must  happen 
in  a  small  pottery,  the  clay  is  out  of  condition,  it 
is  best  remedied  by  cutting  it  with  the  wire  into 
thin  slabs,  piling  them  criss-cross  and  then  wedging 
the  mass.  If  still  streaky,  it  can  be  quickly  tempered, 
piece  by  piece.  A  double  handful  is  torn  across, 
wedged  together  at  a  different  angle  between  the 
hands,  re-torn,  and  re-wedged,  until  hard  and  soft 
are  welded  indistinguishably  together. 

This  thorough  wedging  is  essential,  as  with  begin- 
ners a  small  lump  or  bubble  will  usually  be  sufficient 
to  bring  about  the  collapse  of  the  shape. 

The  clay  being  thoroughly  wedged  is  rolled  into 
balls  of  a  convenient  size.  For  first  practice  they 
should  be  on  the  small  side  and  moderately  tough, 
as  this  allows  a  little  more  play  before  the  ball 
becomes  too  soft.  The  wheel  is  now  started  revolv- 
ing from  right  to  left  (see  cut).  The  head  being 
clean,  the  ball  is  thrown  smartly  onto  its  centre. 
The  hands  are  now  wetted  in  a  bowl  of  water,  which 
is  put,  together  with  the  tools,  on  the  shelf  to  the 
right.  Then  gently  but  firmly,  with  hands  placed 
as  shown  in  Fig.  28,  the  ball  is  centred.  At  this 
stage,  perhaps  the  most  critical  of  all,  the  wheel 
should  revolve  quite  briskly.  The  hands  should 
be  moistened  if  inclined  to  stick  and  the  left  hand 
held  steady,  the  elbow  pressed  into  the  side,  the  fore- 
arm hard  on  the  rest.  The  right  hand  has  more 


63 


CEhT  'RING. 


FIG.  28 

freedom  and  coaxes  the  ball  into  a  half  sphere. 
This  when  dead  centred  is  elongated,  pressed  down 
again,  and  re-formed  into  a  truncated  cone.  The 
left  hand  still  steadying,  the  thumb  of  the  right 
is  pressed  firmly  into  the  centre  of  the  top,  down  and 
out,  to  hollow  the  ball  (see  page  18),  but  stopping 
short  of  the  lathe  head.  At  this  stage  the  most 
convenient  shape  to  form  is  a  cylinder,  its  walls  grad- 
ually diminishing  upwards  with  a  little  fatness  at  the 
rim.  To  do  this  the  wheel  is  slowed  down  a  little 
and  the  fingers  of  the  left  hand  inserted.  The  sides 
are  felt  and  gently  pulled  up,  between  the  left  index 
finger  and  the  two  first  fingers  of  the  right  hand, 
gradually  higher  and  thinner,  always  endeavouring 


64 


PU    JNGUP 


Fio.  29 

to  keep  the  walls  at  an  even  but  slightly  tapering 
thickness.     (Fig.  29.) 

At  first  two  fingers  only  will  be  inserted,  but  as 
the  shapes  grow  in  size  the  whole  of  the  left  hand 
will  gain  admittance.  Then  the  perfect  cylinder 
may  be  modified  to  almost  any  required  form. 
With  narrow-mouthed  shapes  the  opening  must 
be  kept  as  small  as  possible,  for  the  clay  once  pulled 
out  it  is  difficult  if  not  impossible  to  compress  it 
again.  The  centring  and  hollowing  once  mastered, 
the  chief  difficulties  to  avoid  are  getting  the  bot- 
tom of  the  walls  too  thin  before  the  top  is  pulled  up, 
and  making  the  top  wavy  and  irregular.  If  the  lat- 
ter happens,  it  should  be  at  once  cut  back  with  the 


65 


OUT 

SIDE- 

METAL 


pricker,  which  is  also  used  to  test  the  thickness  of 
the  sides  and  base. 

When  the  shape  has  been  pulled  up  to  the  required 
form  and  is  sufficiently  thin,  the  top  is  smoothed 
and  fattened  between  the 
fingers.  This  not  only  im- 
parts a  look  of  substance  to 
the  vase  and  takes  away 
any  cast  look,  but  gives 
strength  where  it  is  most 
needed.  The  inside,  if  wet, 
can  be  cleaned  out  with  the 
stick  sponge  and  the  out- 
side lightly  smoothed  with 
the  other  sponge.  For  the 
insides  of  bowls  or  wide- 
mouthed  shapes,  a  rib  of 
slate  or  zinc  (see  Fig.  30) 
will  be  useful  for  obliterating 
ridges.  The  last  operation 
is  to  pass  the  wire,  held  firmly  to  the  wheel  head, 
beneath  the  pot  and  lift  it  off  and  place  it  on  one 
of  the  pot  boards  or  plaster  discs.  (Fig.  32.) 

The  first  primitive  forms  are  far  better  left  frankly 
for  what  they  are.  Afterwards  when  bigger  and 
more  finished  shapes  are  attempted,  they  can  be 
thinned  and  refined  with  the  aid  of  the  rib  and  a 
modelling  tool,  a  considerable  finish  being  put  on 


OOONE-  EOlk 


INSlDt. 


FIG.  30 


66 


FINISHING 
WITHW 


FIG.  31 


67 


WIRE 
REMOVE 


FIG.  32 

before  they  are  removed  from  the  wheel.  With 
bowls  or  large  shapes  it  will  be  found  impossible 
to  lift  them  off  without  destroying  the  shape  in 
some  degree.  For  these  wood  or  plaster  discs 
will  be  required.  The  plaster  bats  need  soaking 
in  water  before  use  and  the  wood  must  be  three-ply 
to  prevent  warping.  These  discs  are  centred  on 
and  firmly  stuck  to  a  layer  of  clay  run  out  on  the 
wheel  head,  and  when  the  pot  is  finished  they  are 
removed  with  it. 

All   this   sounds   very   simple,   but   the  beginner 
will  do  well  first  to   practise  and   master   centring 


68 

the  ball.  Until  this  be  done,  the  rest  of  the  work  is 
worthless.  After  this  must  be  practised  the  pulling 
up,  the  pressing  down,  and  the  forming  of  truncated 
cones,  then  hollowing  the  ball  and  pulling  up 
into  a  cylinder.  A  true  cylinder  accomplished,  it 
is  easy  to  branch  out  into  simple  wide-mouthed 
vase  forms.  As  the  skill  increases,  shapes  with 
double  curves  and  long  or  narrow  necks  may  event- 
ually be  achieved.  Throwing  to  a  set  copy  induces 
a  necessary  concentration  at  this  stage,  but  once  a 
mastery  is  attained,  shapes  seem  to  suggest  them- 
selves. 

A  small  mirror  placed  so  as  to  reflect  the  true 
form  will  be  found  of  great  service.  When  pairs 
or  several  duplicates  are  required,  a  drawing  of  the 


yTACEy-  FROM-CENTKE  D  BALL 
TOTORNID-yHAPf- 


FIG.  33 


exact  profile  must  be  made  and  a  "rib,"  of  zinc  or 
slate,  filed  to  fit.  Without  such  a  guide  the  match- 
ing up  is  well-nigh  impossible. 

When  watching  a  clever  thrower  in  a  factory  mak- 
ing some  difficult  and  probably  horrible  vase,  it  is 


69 

intensely  interesting  to  see  the  fine  forms  evolved 
in  the  process.  To  the  artist  the  impulse  to  stop 
him  is  almost  irresistible.  It  was  there  that  the 
old  masters  showed  their  wisdom  and  restraint. 
They  stopped  at  the  right  moment  and  none  of 
their  shapes  descend  to  the  merely  clever. 

There  is  a  nobility  about  a  large  vase  lacking  in 
a  small  one.  Once  the  appetite  be  whetted  for  big 
pots  the  desire  for  size  seems  insatiable.  The  only 
way  out,  except  for  the  born  thrower,  is  the  two-  or 
three-piece  vase. 

The  Chinese  were  masters  of  this  as  of  every 
other  process  and  we  find  that  they  frequently  made 
vases  of  quite  moderate  size  in  two  or  three  parts, 
sticking  the  pieces  together  with  consummate  skill. 
This  process,  however,  should  never  be  attempted 
until  considerable  proficiency  has  been  gained  in 
throwing  to  a  drawing,  for  in  any  but  expert  hands 
it  is  doomed  to  failure.  The  shape  must  be  care- 
fully drawn  out  on  paper  and  the  sections  marked 
off  and  then  thrown  exactly  to  size.  Any  deviation 
means  endless  trouble,  with  eventual  disappointment. 

For  this  difficult  work  the  student  unable  to  de- 
vote a  lifetime  to  throwing  will  find  a  removable 
wheel  head  a  necessity.  Then  a  slotted  one  can 
be  screwed  on  which  will  allow  a  plaster  disc  to  be 
shipped  back  into  exactly  the  same  position,  thus  sav- 
ing the  difficult  task  of  re-centring.  For  prolonged 


70 


HALF 


5ECQNDHAL? 


TOP  KEPT 
MOIST 


HALVE5  IN  POSITION     FINISHED  SHAPE 


FIG.  84 

operations  these  plaster  discs  require  to  be  shellacked 
to  prevent  the  work  leaving. 

To  start  with  a  shape  as  shown  in  the  illustration 
might  be  attempted.  (Fig.  34.)  The  drawing  made 
full  size  is  hung  in  full  view.  Then  the  gauge  is  set  to 


71 

the  exact  width  of  the  joint.  The  bottom  half  is 
first  made,  being  cut  square  and  true  with  the  pricker. 
The  drawing  is  reversed  and  the  upper  half  thrown, 
the  neck  being  at  the  bottom  with  a  fair  amount  of 
waste  beneath.  When  each  part  is  trimmed  accu- 
rately to  measure,  they  are  put  aside  to  toughen. 

The  top  portion  will  stiffen  just  as  required,  leav- 
ing the  neck  still  moist.  The  bottom  half  will  need 
watching  to  prevent  the  upper  edge  drying  before 
the  base  gets  firm  enough  to  support  the  top  when 
attached.  A  damp  cloth  lightly  wrapped  round 
it  will  help  to  insure  the  ideal  condition  for  sticking 
up,  which  is  a  gradually  diminishing  state  of  toughness 
from  the  base  up  to  lip,  the  junction  of  the  parts 
being  in  exactly  the  same  state. 

When  fit  to  handle,  the  top  half  is  cut  through 
at  the  lip,  allowing  a  trifle  for  finishing  off.  Next 
the  bottom  half,  still  firmly  fixed  to  the  bat,  is 
slotted  back  into  its  original  position  on  the  wheel. 
The  flat  surfaces  that  have  to  be  applied  and  stuck 
are  now  very  carefully  and  slightly  roughened, 
then  painted  with  thick  slip  made  from  the  same 
body.  These  two  wet  edges  are  now  applied  and 
gently  and  firmly  pressed  into  position,  the  wheel 
being  slowly  revolved  to  see  if  the  two  halves  run 
true.  When  well  together  and  apparently  sticking, 
a  little  wedge  of  soft  clay  can  be  carefully  run  in  all 
around  the  joint.  This  operation  should  be  very 


thorough,  and  the  clay  wedge  must  be  carefully 
welded  into  the  sides  of  the  joint.  This  is  finished 
off  on  the  outside  with  the  rib  and  the  inside  very 
lightly  smoothed  with  the  fingers.  During  this 
process  the  top  should  be  covered  with  a  soft  wet 
cloth,  then  when  the  joint  has  been  made  good  and 
will  stand  the  slight  strain,  the  lip  is  finished  off 
in  the  ordinary  way.  With  three-pieced  shapes  the 
lip  can  be  finished  before  sticking  up,  as  the  last 
part  is  thrown  in  its  right  position.  If  at  any  time 
the  shape  shows  a  disposition  to  leave  the  plaster 
bat,  it  should  be  stuck  down  with  wet  clay.  The 
toughened  shape  can  now  be  turned  down  in  its 
upright  position,  cut  off  the  bat,  and  the  base  hol- 
lowed in  a  chuck  (see  next  chapter). 


Ipdia.     B.  <?.  2000 


CHAPTER  VII 

TURNING  OR  SHAVING 
"A  sharp  spear  needs  no  polish."  —  Zulu  proverb. 

THE  turning  or  shaving  operation  takes  place 
when  the  green  shape  has  dried  to  a  leathery  condi- 
tion. It  consists  in  shaving  the  sides  and  hollow- 
ing the  base  until  the  thickness  is  uniform.  The 
shape  is  thus  made  much  lighter  and  rendered  less 
liable  to  crack  from  unequal  contraction.  At  the 
same  time  a  fine  finish  is  imparted  to  the  surface. 

One  of  the  handiest  tools  for  shaving  is  shown 
in  Fig.  27,  no.  6,  but  a  piece  of  hoop  iron  bent  at  right 
angles  and  shaped  with  a  file  will  serve.  Small  hol- 
lows can  be  finished  with  a  modelling  tool.  An  old 
piece  of  leather  will  close  up  and  finish  the  surface. 
In  factories  a  horizontal  lathe  is  usually  employed, 
the  shape  being  fitted  over  a  chum  or  chuck.  Skilled 
men  can  turn  shapes  down  until  they  are  scarcely 
thicker  than  tin,  but  this,  it  is  needless  to  add,  is  an 
abuse  of  method  even  with  porcelain,  and  quite 
out  of  place  with  stoneware  or  earthenware.  All 
that  is  necessary  is  to  trim  the  thick  sides,  hollow 
the  base,  and  smooth  the  surface.  (Fig.  35.) 

73 


.ACTION 

./HEWING 

TURNED  ^ 

THROWN 

WALL  OF 

.A/HAPE 


A  simple  way  to  arrive  at  this  is  to  throw  on  the 
wheel  a  chuck  of  stiff  clay  to  fit  the  shape,  wide- 
mouthed  ones  being  fitted  over  and  ordinary  shapes 

within  the  chuck.  (Figs. 
36  and  37.)  A  piece 
of  soft  linen  is  placed 
over  this  chuck  to  pre- 
vent sticking  and  the 
shape  fitted  and  centred. 
When  spinning  quite 
truly  from  right  to  left 
and  steadied  with  the 
left  hand,  the  tool  should 
be  gently  applied  as 
shown  in  the  illustra- 
tion. Hollow  the  base 
and  then  shave  the  sides,  turning  all  down  very 
gradually  and  improve  the  outline  as  much  as  pos- 
sible in  the  process. 

Care  must  be  taken  with  the  base.  If  it  is  not  quite 
true  it  should  be  sandpapered  to  stand  flat.  A  little 
experience  will  soon  show  when  it  is  in  the  best 
state  for  shaving.  If  the  clay  is  too  soft,  the  tool 
jumps,  forming  ridges,  or  possibly  cuts  deeply  into 
the  form.  If  it  is  too  dry,  the  surface  crumbles 
and  the  pot  is  liable  to  break.  When  turned  in 
the  right  leathery  condition,  the  shavings  curl  off 
like  peel  from  an  apple  and  all  tool  marks  are 


FIG.  35 


75 


VING 
J3A5E< 


FIG.  36 


76 

easily  removed.  A  beautiful  finish  may  then  be 
imparted  with  the  leather. 

To  end  the  process  the  shape  is  reversed  in  the 
chuck.  Those  most  important  parts,  the  shoulders 
and  lip,  are  carefully  rounded  with  a  piece  of  felt 
and  polished  with  the  leather.  Properly  attended 
to,  this  will  save  much  work  and  disappointment 
later  on.  Then  with  all  holes  filled  up,  all  ridges, 
bumps,  and  sharp  edges  removed,  the  shape  is  signed 
and  put  to  dry. 

For  very  delicate  work  in  transparent  glaze  or 
under-glaze  painting,  the  whole  surface  may  be 
gone  over  with  very  fine  sandpaper  and  polished 
with  the  hand.  This  may  be  done  provided  the 
body  is  a  fine  one,  for  with  a  coarse  body  this  is 
apt  to  leave  the  surface  looking  gritty.  Some  little 
practice  will  be  necessary  in  throwing  stiff  chucks 
and  centring  the  shape  securely,  but  this  once  mas- 
tered, the  method  here  described  will  be  found  to  be 
expeditious  and  satisfactory  for  turning  shapes. 

A  proper  regard  for  process  points  to  the  desir- 
ability of  leaving  built  shapes  without  a  high  finish. 

Yet  they  also,  if  built  carefully  and  stoutly,  may 
be  turned  down  in  the  above  manner.  The  building 
up  and  turning  down  is  somewhat  tedious,  but  it 
is  sometimes  the  only  way  by  which  a  craftsman 
can  obtain  large  shapes.  A  rather  more  simple 
process  is  to  centre  the  shape  upon  a  whirler  and 


77 


SHAVING 

THE 

5IDE5 


FIG.  37 

turn  down  with  a  sharp  wire  tool,  finishing  off  lightly 
with  a  sponge  and  soft  leather. 

To  accomplish  this  satisfactorily  the  shape  must 
be  fairly  soft,  as  there  can  be  no  quick  spinning 
motion  to  enable  the  tool  to  cut  cleanly  as  in  the 
chuck  or  the  wheel.  When  the  head  of  the  whirler 


78 


OSITION 
OOL/ WHEN 


FIG.  38 

is  of  plaster,  it  should  be  well  soaked  in  water  and 
the  centred  shape  stuck  down  with  soft  clay.  The 
hand  holding  the  cutting  wire  tool  must  be  held 
steady  at  a  fixed  distance  from  the  centred  shape 
and  the  pot  may  be  sprayed  with  water  blown 
through  a  diffuser  from  time  to  time,  to  keep  it 
moist.  Some  clays  will  not,  however,  stand  much 
re-wetting. 

It  should  not  be  necessary  to  caution  the  crafts- 


79 

man  against  angular  profiles,  splayed  feet,  or  sharp 
mouldings.  Such  features  are  foreign  to  good  pot- 
tery, however  suited  to  metal  or  stone. 

With  taste  and  judgement  the  irregular  grooving 
caused  by  the  tool  can  be  made  of  high  decorative 
value.  In  no  case  should  the  built  shape  try  to 
masquerade  as  a  thrown  shape.  When  the  whirler 
is  used  to  shave  down  built  shapes,  they  may  be 
coiled  very  thick  at  the  base,  thus  allowing  more 
rapid  work. 

The  attention  must  then  be  concentrated  on  the 
profile  of  the  inside.  In  this  way  many  shapes 
that  splay  out  or  curve  boldly  from  the  foot  may  be 
built,  which  would  otherwise  present  many  diffi- 
culties in  coiling. 


CHAPTER  VHI 

TILE-MAKING 

"VI  thousand  and  fourscore  of  pavynge  tiles  delivered  at 
Hampton  Court,  for  to  pave  the  Kinges  new  hall  at 
XXVJs.  VlUd.  the  thousand." 

—  Sixteenth  century  memorandum. 

TILES  may  be  made  of  various  kinds  and  sizes, 
but  in  every  case  they  show  an  inclination  to  buckle 
in  drying  and  firing.  The  larger  the  tile  the  stronger 
is  this  tendency  to  warp.  The  clay  must  not  be  so 
rich  as  that  which  is  used  for  throwing  and  should 
be  tempered  to  counteract  the  tendency  to  curl. 

A  tile  box  as  shown  in  Fig.  39,  or  a  variant  of  it,  will 
be  required  for  pressing  tiles  by  hand ;  for  plain  tiles 
f "  deep,  for  others  l£"  deep,  the  size  being  calcu- 
lated to  allow  for  shrinking.  The  sides  hinge  and 
the  thumb  screws  keep  it  steady  on  the  bench  during 
work.  For  rough  tiles,  two  strips  nailed  to  the 
table  will  serve,  the  clay  being  rolled  out  between 
and  cut  in  lengths  as  required. 

For  plain  tiles  the  wedged  and  tempered  clay 
is  batted  out  into  a  slab  a  full  f  "  thick.  The  mould 
is  dusted  with  French  chalk,  flint,  or  very  finely 

80 


81 


HINGE 
\ 


PIN 


THCJMB 


MOVABLE 
3AK 


UP. 


RULE 


CATCH 


FIG.  39 

sifted  clay  dust,  to  prevent  sticking,  and  into  it  is 
pressed  a  piece  cut  to  fit  easily  in  the  tile  box,  from 
the  slab.  This  is  firmly  pressed  into  the  box,  con- 
siderable pressure  being  used.  The  surplus  is  scraped 
off  and  the  top  trued  with  an  iron  straight-edge. 
The  knife  can  be  run  round  the  sides,  then  with  the 
frame  reversed  a  smart  tap  on  the  back  will  release 
the  tile. 

Let  the  tiles  toughen  and  then  pile  in  stacks  with 
flat  pieces  of  clay  or  old  tile  between  each  corner 
and  a  true  biscuit  tile  at  bottom  and  the  top.  They 
can  be  piled  one  on  the  other  with  sand  between 
or  stacked  like  bricks  with  alternate  holes  for  the 


82 

air  to  circulate.  This  retards  the  drying,  but  in 
any  case  they  must  be  dried  slowly.  With  plain 
glazed  tiles  a  little  coarse  dust  sprinkled  over  the 
surface  before  the  tile  is  removed  from  the  box,  and 
well  pressed  in,  will  give  a  slight  interest  to  the  sur- 
face and  take  away  any  mechanical  look.  If  re- 
quired for  painting,  the  clay  must  be  very  finely  sieved 
and  the  surface  will  need  careful  finishing  by  hand 
when  dry.  With  coarse  clay,  a  fine  surface  can  be 
imparted  with  a  flexible  broad  palette  knife. 

For  raised  outline  tiles  a  frame  1}"  deep  is  re- 
quired. This  allows  a  plaster  bat  f "  thick  to  be 
placed  at  the  bottom.  The  best  way,  perhaps,  is 
to  oil  the  frame  and  cast  the  bat  in  it,  removing  it 
when  set  and  sandpapering  the  upper  surface  flat 
and  true.  The  design  for  the  tile  drawn  the  exact 
size  on  paper  is  now  traced  on  this  surface.  It  is 
far  better  to  sketch  it  directly  onto  the  slab,  but  this 
demands  some  proficiency  if  the  surface  is  to  be 
preserved.  The  design  is  then  incised  with  a  firm 
sharp  point,  clay  squeezes  being  taken  from  time 
to  time  to  show  the  progress  of  the  work.  The 
plaster  should  be  wetted  to  insure  easy  working. 
At  the  finish  the  design  should  stand  out  in  a 
fairly  strong  and  deep  line  —  square  —  not  round 
or  angular  in  section.  (Fig.  40.)  A  chisel-pointed 
hard  pencil  will  be  found  best  for  finishing.  This 
gives  a  clear-cut  line,  not  too  round.  The  bat, 


83 


/      GLAZE 
PL    /_  V 


A-POINTFOK-rarroqTLINE 
OEOK  FINAL  INCl/ED  LINE 
Ot  INCOUECT 

J> 


FIG.  40 

sponged  clean  and  porous,  is  then  placed  in  the 
frame  and  the  tile  pressed  as  before. 

Raised  outline  tiles  can  be  even  more  satisfactorily 
made  by  means  of  outlining  slip  squeezed  from  a 
tube  or  tracer  in  the  same  manner  that  inscriptions 
are  made  on  sugared  cakes,  but  this  requires  much 
practice  to  obtain  good  results.  When  glazing, 
the  coloured  glazes  are  applied  to  the  different 
compartments  with  a  brush.  As  the  glaze  fuses 
to  about  one  third  of  its  bulk  when  dry,  it  should 
be  applied  very  liberally. 

It  will  be  found  that  large  or  elaborate  designs 
are  to  be  avoided,  as  in  this  process  they  tend  to 


84 


NOZZLE5 


SLIPTRACEBS 


Fio.  41 

become  mechanical  and  look  thin.  The  old  Spanish 
and  Moorish  tiles  in  this  style  with  jewel-like  bits 
of  colour  are  excellent  guides  and  might  be  studied 
with  advantage. 

The  process  of  making  encaustic  tiles  is  a  little 
more  complicated.  Within  the  frame  is  placed  a 
well-lathered  or  soaped  plaster  bat  (or  tile)  high 
enough  to  allow  only  a  thin  layer  of  clay  \"  thick 
being  run  out  on  top.  On  this  when  firm  the  design 
is  traced  or  pounced.  Then  with  a  thin  sharp  blade 
it  is  cut  down  vertically  to  the  plaster  bat,  and  the 
clay  removed  until  the  whole  design  shows  in  white 
plaster  beneath  (see  illustration  42).  The  face  of 
the  clay  left  must  be  preserved  carefully,  as  it 
forms  the  surface  of  the  subsequent  press. 

The  bat  with  clay  is  now  placed  on  the  bottom  of 
the  frame  to  allow  a  cast  f "  thick  to  be  made.  The 
plaster  and  the  sides  of  the  frame  are  slightly  oiled 


85 


HINGE 


CLAY  LAtfEn  CUT 

OUT  ON  BAT 


%£• 


BM 


FIG.  42 

and  the  plaster  mixed  and  poured  in.  A  soft  hair 
brush  will  be  useful  to  dislodge  the  air  bubbles  that 
are  certain  to  hide  in  some  of  the  many  odd  corners. 
When  nearly  set,  the  surface  of  the  plaster  can  be 
scraped  flat,  and  when  set  taken  out  of  the  frame  and 
detached.  The  clay  is  picked  out  and  the  whole 
surface  of  the  design  cleaned  and  trimmed  so  that 
it  will  not  hold  or  bind  in  pressing.  This  in  turn 
is  placed  in  the  frame  and  a  careful  press  taken. 
The  result  is  a  sunk  design  into  which  a  different 
coloured  clay  is  pressed,  the  tile  being  first  allowed 
to  toughen.  The  surface  is  lightly  scraped  flat 
and  the  tile  slowly  dried.  When  hard,  the  face  is 
scraped  again  with  a  steel  straight-edge,  sandpapered, 
and  dusted,  when  the  design  appears  in  two  colours. 
(Fig.  43.) 
The  most  effective  clays  are  fairly  siliceous  reds, 


86 


OEF  E^a  or  TILE 

IN  FRAME  VtCTION  ON  AB 


FIG.  43 

buffs,  browns,  and  greys.  When  tempered  with 
flint  or  quartz  sand  to  a  uniform  degree,  they  offer 
a  splendid  opportunity  for  counterchange  pattern. 
If  a  soft  clay  that  contracts  considerably  is  inlaid 
in  a  refractory  clay,  cracks  will  appear  round  the 
edges  of  the  inlay.  Thus  it  is  found  best  to  have 
the  body  of  the  tile  made  of  the  clay  that  contracts 
most. 

Where  only  a  single  tile  is  required  a  more  direct 
method  is  possible.  The  tile  is  pressed  and  allowed 
to  toughen  slightly,  the  design  being  transferred  as 
before.  It  is  then  cut  round  with  a  sharp  knife 


87 

and  the  waste  removed  with  a  wire  tool.  A  certain 
facility  of  handling  is  required,  for  great  care  must 
be  taken  to  preserve  the  edges  and  angles.  This 
method  is,  however,  productive  of  much  fresh  and 
vigorous  work. 

Encaustic  tiles  must  necessarily  be  simple  and  bold 
in  character,  for  anything  complicated  invites  con- 
fusion; the  best  possible  guides  are  the  encaustic 
tiles  of  mediaeval  times,  especially  the  simple  and 
spirited  English  and  German  Gothic. 

The  most  satisfactory  way  to  make  modelled 
tiles  or  panels  is  to  run  out  upon  a  stout  board,  cross 
battened  to  prevent  warping,  a  flat  slab  of  clay  of 
the  required  thickness.  Sketch  in  the  design  with 
a  point  and  model  straight  away  onto  the  clay. 
Care  must  be  taken,  if  the  panel  is  to  be  fired,  to  see 
that  all  the  added  work  adheres  firmly  to  the  back- 
ground. Where  several  presses  are  to  be  made,  the 
edges  of  the  modelled  slab  should  be  carefully 
trimmed  with  a  bevel,  the  board  oiled,  and  the  mould 
made  directly  after  the  modelling  is  finished.  The 
mould  may  be  worked  on  in  moderation.  Letter- 
ing is  much  more  easily  incised  in  the  mould  than 
raised  in  the  clay.  For  tiles  needing  much  sharp- 
ness of  detail  almost  the  whole  can  be  carved  in 
the  plaster.  Unless  done  with  great  sympathy, 
however,  this  leads  to  a  certain  harshness  and  angu- 
larity that  should  be  foreign  to  clay.  Where  a 


88 

moulded  frame  for  a  panel  is  required,  a  strickle,  or 
profile,  is  cut  in  zinc.  For  short  use  one  made  from 
a  thin  slab  of  plaster  will  serve.  The  strickle  is 
keyed  to  a  straight-edge  and  dragged  over  the  clay 
until  the  correct  moulding  emerges.  This  is  then 
cut  into  lengths  and  very  carefully  dried. 

The  tendency  of  all  transparent  glassy  glazes  to 
pool  in  hollows  and  run  off  at  high  points  must  be 
borne  in  mind.  With  thick  matt  glazes  any  deli- 
cacy of  detail  is  apt  to  be  lost  labour.  These  prob- 
lems should  be  faced  before  the  design  is  made,  as  in 
this  process  there  is  a  certain  quality  of  surface 
required  by  the  glaze.  On  the  other  hand,  in  en- 
deavouring to  make  a  good  surface  for  the  glaze  to 
enhance,  it  is  easy  to  slip  into  the  over-round  and 
slimy  treatment  that  characterizes  so  much  modelled 
pottery. 


CHAPTER  IX 

DRYING  :    FINISHING 

"There  nis  no  workeman  whosoever  he  be 
That  can  werke  bothe  welle  and  hastile." 

—  "Merchants  Tale." 

DRYING  out  is  quite  an  important  part  of  pot 
making.  For  this  a  drying  cupboard  is  a  necessity. 
It  is  easily  erected,  if  the  front  and  sides  of  wood  be 
backed  against  a  wall.  Across  the  bottom,  which 
should  be  open,  run  a  row  of  gas  jets  protected  above 
by  perforated  zinc  or  iron.  At  the  top,  which  is 
boarded  in,  place  a  small  sliding  panel  to  insure  a 
draught.  With  side  brackets  and  removable  shelves 
it  should  answer  all  purposes.  A  cupboard  may  be 
built  over  a  radiator,  but  here  the  heat  is  not  so 
easily  regulated. 

A  thermometer  inside  the  cupboard  will  be  an 
advantage,  for  a  wet  pot  straight  from  the  wheel 
will  warp  in  a  warmth  that  would  be  quite  suited 
to  tough  shapes.  The  green  or  damp  wares  should 
be  put  on  the  top  shelves  and  brought  nearer  the 
heat  as  they  dry.  Large  shapes  put  into  the  cup- 
board to  dry  quickly  are  very  liable  to  crack  across 


90 

the  base.  Any  flush  of  heat  upon  them  through  any 
aperture  in  the  shelves  will  cause  them  to  dry  streak- 
ily.  Turning  then  becomes  difficult  or  impossible. 

Bowls,  if  not  too  fragile,  may  with  care  be  piled 
one  within  the  other.  This  helps  to  retain  their 
shape.  Tiles  are  best  stacked  in  piles  dusted  with 
flint  or  with  a  piece  of  clay  at  each  corner  between 
them.  Tiles  should  never  be  placed  in  the  cupboard 
until  quite  dry  and  straight.  Flat  platters  or  dishes 
require  very  careful  drying  to  prevent  buckling  and 
should  be  reversed  on  a  piece  of  sanded  glass.  When 
shapes  are  dried  in  the  open  air,  they  often  get  hard 
at  the  rim  before  the  bottom  stiffens.  They  need 
reversing  to  counteract  this  tendency. 

To  retard  drying,  which  may  often  be  necessary, 
a  damp-box  is  needed.  A  large  box,  zinc-lined  and 
fitted  with  plaster  slabs,  is  an  excellent  device.  The 
plaster  must  be  kept  moist  with  water.  A  well- 
tarred  box  with  a  close-fitting  lid  is  more  easily 
constructed  and  will  serve  most  purposes.  All 
work  to  be  stuck  up  or  modelled  on  should  be  kept 
in  the  damp-box  until  quite  finished  and  then  dried 
very  gradually. 

In  all  kinds  of  sticking  up  the  body  and  the  addi- 
tion should  be  of  the  same  consistency.  Re-wetting 
is  dangerous  but  may  be  resorted  to  in  moderation 
with  stout  thrown  shapes.  Ornament  added  when 
the  shape  is  nearly  dry  is  very  likely  to  leave  in  the 


91 

biscuiting,  although  apparently  quite 
firm  in  the  green  state.  Cast  shapes 
dry  very  rapidly  and  should  be  fin- 
ished before  they  become  white  dry. 
With  practice  handles,  masks,  and  the 
like  can  be  affixed  in  the  dry  state  with 
slip,  but  it  demands  its  careful  and 
sparing  use.  Cracks  or  holes  in  dried 
shapes  can  with  great  care  be  filled,  a 
stiff  wedge  of  clay  being  firmly  pressed 
in  and  welded  to  the  slightly  moistened 
sides  of  the  crack.  The  plaster  tools 
(Fig.  44)  will  be  found  very  handy  for 
working  on  the  dry  clay.  With  skill 
and  patience  much  repairing  may  be 
done  on  unfired  shapes,  but  it  is  waste 
of  time  to  attempt  it  unless  the  beauty 
of  the  piece  warrants  it.  It  is  far  better 
if  the  piece  be  faulty  to  throw  it  back 
into  the  bin  at  this  stage.  Once  fired,  it 
is  likely  to  remain  an  irremediable  eye- 
sore. 

One  or  two  other  points  bearing  on 
finish  have  been  mentioned  before  in 
previous  chapters,  but  these  last  touches 
are  so  important  that  they  will  bear 
some  reiteration.  TOOL5 

The  finality  burned  in  by  the  biscuit-        FIG.  44 


92 

ing  should  induce  a  careful  and  sound  completion  of 
each  object ;  yet  paradoxical  as  it  may  seem,  the  less 
finishing,  the  better  for  the  piece.  It  is  no  part  of  a 
craftsman's  work  to  go  finnicking  with  file  and  sand- 
paper ;  too  frequently  nothing  remains  of  what  might 
have  been  a  vigorous  shape  but  a  meticulous  finish. 
The  best  Japanese  work  was  superb  in  this  re- 
spect and  despite  the  many  quaint  and  surprising 
shapes  into  which  they  fashioned  the  clay,  it  very 
rarely  seems  to  lose  its  plastic  character,  it  never 
assumes  forms  more  suited  to  metal,  wood,  or  stone. 
Again  the  character  that  comes  with  correct 
treatment  is  never  smothered.  Often  the  ribs  or 
ridges  made  by  the  fingers  or  the  tool  in  forming 
the  shape  are  frankly  left  to  contribute  their  quota 
to  the  general  effect.  The  lips  are  rounded  with 
scrupulous  care  and  angles  removed  without  a  sug- 
gestion of  weakness. 

Where  large  utensils,  ewers  and  the  like,  are  in 
question,  mediaeval  pottery  is  rich  in  suggestion 
for  handles,  spouts,  and  such  added  forms.  It 
is  only  when  such  additions  are  affixed  that  one 
realizes  the  nicety  of  adjustment  required  between 
the  size,  shape,  and  situation  of  the  handle  or  spout 
and  the  vessel  to  which  it  is  attached.  It  is  here 
that  an  appreciation  and  an  intelligent  use  of  his- 
toric ornament  is  necessary. 


CHAPTER  X 

FIRING  BISCUIT 

"The  Pope  the  Cardinals,  and  the  Princes  of  the  World  are 
astonished  that  such  excellent  and  noble  works  can  be 
made  out  of  the  earth." 

—  EXIMENUS.     Fifteenth  century. 

WHEN  sufficient  green  shapes  have  been  accumu- 
lated and  are  white  dry,  the  next  stage  will  be  biscuit- 
ing.  This  process  is  the  firing  of  the  clay  to  a  prim- 
rose or  a  white  heat  according  to  its  fusibility. 
This  permanently  expels  the  water  that  is  always 
present,  even  when  dry,  and  converts  the  friable 
clay  into  a  hard  unalterable  body.  This  may  vary 
in  colour  from  the  white  of  kaolin  to  ivory,  grey, 
buff,  red,  or  brown,  according  to  the  composition 
of  the  clay;  it  may  be  vitreous  or  porous;  soft 
like  common  flower  pots  or  so  hard  that  it  will 
spark  when  struck  with  steel. 

The  fire  is  the  ultimate  test  of  the  pot  and  of  the 
potter.  It  is  indispensable  to  both.  With  but  a 
small  kiln  the  craftsman  will  begin  to  appreciate 
many  things  that  can  be  learned  only  at  the  fire  hole. 
Without  a  kiln  he  will  not  commence  to  be  a  potter. 

93 


94 


CAS 

KILN' 


5HAPL  ONTU.L 


»   INSlDt&CAST 
JHAPL  ONTO?. 

B.CONE5" 
O  HEAVY  POT 
(SMALL  INSIDC) 

DTlLLJONJA 
•DDLLf-nRLD- 
TILL  Ot^TOP- 

F1WL3R1CK 
CASL 

SHUT  IKON 
CASING- 

JECTION  OF 


FIG.  45 

The  kinds  of  kilns  usually  found  in  schools  are 
the  gas  and  the  oil  kiln.  The  English  gas  [kiln  has 
an  arrangement  of  nine  or  twelve  burners  beneath 
the  muffle.  (Fig.  45.)  This  is  a  fire  clay  box,  open 
at  the  front,  set  on  fire  bricks  and  cased  round  with 
fire  tiles  within  an  iron  frame  (see  cut).  There  is 
an  air  space  all  round,  except  at  the  open  end,  lead- 
ing to  the  flues  on  top  which  have  dampers  to 
regulate  the  draught.  The  open  end  may  be  closed 
by  a  hinged  door  or  bricked  up  with  fire  tiles  cut 
to  fit.  The  defects  of  this  kind  of  kiln  are  too  sud- 
den access  of  flame  to  the  bottom  of  the  muffle, 
causing  it  to  split,  and  the  impossibility  of  getting  the 
front,  where  trials  are  usually  placed,  fired  up  equally 


95 

[with  the  back.  An  ideal  muffle  of  this  kind  would 
!be  one  with  flues  all  round,  gradual  access  of  flame 
ion  all  sides,  spy  holes  each  end,  and  the  top  to  lift 
off,  for  placing.  American  kilns  have  flues  in  the 
door,  and  the  chimney  at  the  top  is  placed  slightly 
forward,  thus  making  it  easy  to  fire  the  front  up 
hard.  They  are  usually  fitted  with  two  large 
burners,  with  air  mixers,  and  a  handy  mica  spy  hole. 

The  oil  kiln  differs  considerably  from  the  gas 
kiln.  The  oil  is  fed  through  tubes  into  fire  boxes 
some  distance  below  the  bottom  of  the  muffle.  It 
burns  on  asbestos  fibre  in  an  iron  pan  to  which  the 
draught  can  be  admitted.  The  flames  strike  the 
bottom  of  the  muffle  and  pass  up  through  fire  clay 
pipes,  which  project  into  the  muffle,  then  pass  off 
through  a  twin  flue  regulated  by  dampers.  With 
this  kiln  a  long  flue  is  necessary  and  any  excess  of 
carbon  is  liable  to  choke  the  pipes,  and  further  it 
cannot  be  "sweated"  up  at  the  finish  so  easily  as  a 
gas  kiln  having  a  large  number  of  burners. 

It  is  a  good  plan  when  a  coarse  fire  clay  muffle  is 
used  for  glaze  and  biscuit  to  give  the  sides  and  top 
a  sagger  wash  of  lead  and  stone.  This  renders 
the  muffle  less  liable  to  absorb  glaze  from  the  pots 
in  glost  firing.  It  also  lessens  the  danger  of  small 
bits  scaling  off  and  sticking  to  the  finished  ware. 
The  bottom  should  always  be  kept  dusted  with 
finely  powdered  flint.  When  cracks  appear  or 


96 

joints  open,  they  should  be  stopped  with  a  pugging 
of  fire  clay  and  grog.  A  mixture  of  egg  silica  or 
water  glass  with  fine  grog  and  quartz  sand  will 
stop  small  cracks.  Siluma,  a  fire-proof  cement, 
with  equal  parts  of  sand,  answers  admirably  for 
patching. 

In  biscuit  firing  the  green  shapes  may  be  packed 
close  together,  with  the  lighter  shapes  on  top  of  the 
stronger,  but  all  must  be  J"  to  f  "  away  from  the 
sides  of  the  muffle.  Triangular  pieces  of  biscuit, 
called  saddles,  are  used  to  raise  the  shapes  off  the 
bottom,  but  often  a  fired  tile,  sanded  and  placed 
on  a  spur  or  saddles,  gives  the  best  foundation. 
Where  two  layers  are  required,  small  props  and  fire 
bats,  perforated  to  let  the  heat  through,  will  be 
necessary.  These  form  shelves  as  the  exigencies 
of  the  packing  dictate.  (Fig.  47.) 

For  light  shapes,  thimbles  and  fired  tiles  will 
serve  the  purpose.  (Fig.  48.)  Where  a  shelf  or  prop 
rocks  insecurely,  a  small  wad  of  pugging  (grog  and 
clay)  will  give  a  steady  bearing.  Thrown  bowls, 
if  dried  together  and  well  fitting,  may  be  fired  to- 
gether, and  large  thrown  pots  may  be  filled  with 
little  ones.  Cast  shapes  can  be  placed  on  top  of 
thrown  ones,  but  no  liberty  is  to  be  taken  with  them. 
Flint  should  be  used  liberally  to  prevent  sticking, 
which  may  happen  if  the  biscuit  be  over-fired. 
Tiles  can  be  fired  two  together  in  tile  boxes  or 


97 

stacked  as  dried.  Flat  ware  fired  in  a  small  muffle 
requires  very  careful  handling.  Whenever  possible, 
it  should  be  placed  in  the  centre,  on  a  flat  flint- 
covered  fire  tile  or  bat. 

One  soon  learns  to  pack  a  biscuit  kiln,  using  sad- 
dles, spurs,  stilts,  thimbles,  bits  of  tile  or  biscuit, 
and  sand  or  flint  as  necessary.  The  thing  that  is  a 
little  difficult  to  realize  at  first  is  that  built  or  thrown 
shapes,  and  still  less  tiles  or  modelled  work,  should 
not  be  hurried.  Twelve  hours  is  none  too  long  to 
give  to  a  f "  tile  in  the  biscuit  kiln.  Although  to  all 
appearances  thoroughly  dry,  the  least  hurry  gen- 
erates steam  which  will  ruthlessly  blow  our  best 
effects  to  bits.  In  packing,  two  cones  or  temperature 
indicators  (Fig.  46)  are  placed  somewhere  near  the 
middle  in  a  position  easily  seen  during  the  firing 
from  the  spy  hole. 

These  cones  are  made  of  different  compositions 
which  melt  at  varying  temperatures.  Thus  if  the 
firing  point  of  a  body  is  known,  a  cone  of  that  degree 
is  used  and  the  firing  continued  until  the  cone 
bends.  This  it  does  soon  after  it  assumes  the 
colour  of  the  surrounding  muffle. 

To  eliminate  the  uncertainty  that  is  likely  to  be 
present  at  the  first  few  firings  it  is  as  well  to  use  two 
or  even  three  cones,  one  just  above  and  one  below 
the  correct  temperature.  Placed  in  order  there  is 
little  chance  then  of  over-  or  under-firing  unless  so 


98 


CONE./: 


ERECT    5HRUNK.ifNT.  COLLAB/fD. 


FIG.  46 

much  sulphur  gets  into  the  kiln  that  the  cones 
harden  and  refuse  to  turn.  Calorites  are  sometimes 
used  but  arevnot  so  reliable.  The  cones  may  be 
sloped  to  insure  bending  to  right  or  left,  as  a  cone 
bending  towards  the  spy  is  deceptive. 

A  trial  piece  of  biscuit  being  placed  near  the  spy 
hole,  the  next  thing  is  to  close  the  muffle.  In  a 
kiln  with  hinged  doors  the  spy  hole  is  fixed  and  this 
fact  has  to  be  taken  into  account.  But  with  a 
bricked-up  door  the  spy  and  vent  may  be  left  where 
it  is  most  convenient.  These  orifices  have  plugs 
that  fit  them  loosely  so  that  if  necessary  they  can 
be  pulled  without  disturbing  the  clamming.  This 
clamming  or  stopping  is  a  mixture  of  sand,  sieved 
dust,  ground  pitchers,  or  other  infusible  siftings  held 


99 

together  with  a  very  little  waste  glaze  and  water. 
Where  much  is  required,  moist  sand  will  suffice. 
This  is  plastered  into  the  cracks  that  would  other- 
wise let  heat  out  of,  or  air  into,  the  muffle,  and  so 
seals  up  the  door.  With  hinged  doors  little  stopping 
is  required,  except  round  the  spy  or  vent.  The 
crack  above  the  door  should  not  be  clammed  until 
the  muffle  begins  to  get  warm.  With  this  done  and 
the  two  plugs  out,  all  is  now  ready  to  light  up. 

With  an  English  kiln,  a  good  middle  course  is 
as  follows  :  For  cone  .01,  taking  12-14  hours.  See 
that  all  the  burner  taps  are  off  with  the  main  cock 
on  one  third  to  one  half.  Take  the  reading  of  the 
metre.  Pull  the  air  regulators  right  back  and  the 
dampers  out  nearly  half.  Then  take  out  the  plug 
of  the  lighting  hole  and  insert  a  taper.  Turn  on 
tap  number  1.  When  lit,  withdraw  the  taper  and 
turn  on  tap  number  2.  Turn  down  to  about  one 
half  and  continue  until  every  burner  is  lit,  making 
sure  that  each  one  is  burning  freely  with  a  yellow 
flame.  With  a  kiln  having  twelve  burners  turn 
out  all  but  numbers  3,  6,  and  9.  With  these  on 
one  third,  very  gently  push  forward  the  air  regu- 
lators until  a  roaring  noise  tells  that  air  is  being 
admitted  to  the  bunsen  burners. 

The  flame  at  this  time  should  be  blue,  and  the 
stopper  should  be  replaced.  If  the  flame  appears 
at  all  fierce,  turn  the  taps  down  a  little.  If  turned 


100 


BATS  Si  PROPS 


FIG.  47 

down  too  much,  the  gas  lights  back  and  will  have 
to  be  turned  out  and  relighted.  The  same  thing 
happens  when  too  much  air  is  admitted.  The  burn- 
ers require  watching  until  the  right  pressure  is 
known. 

For  biscuit  of  any  thickness  three  hours  on  the 
three  burners  is  not  too  much,  the  taps  being  grad- 
ually turned  on  to  increase  the  length  of  the  flame 
until  at  the  end  of  the  three  hours  the  taps  are  at 
three  fourths.  At  the  end  of  the  first  half  hour  the 
bottom  spy  hole  is  plugged  and  when  all  steam  has 


101 


LIGHT  BAT 


ipped  issuing  from  the  top  vent,  that  is  stopped 
so  and  the  whole  clammed,  leaving  just  a  small 
crack  as  vent.  When  three  hours  are  up,  the  regu- 
lators are  pulled  back  and 
all  burners  lit  at  half  cock. 
Then  all  but  2,  5,  7,  9,  and 
1 1  are  turned  out.  Starting 
at  the  half,  they  are  grad- 
ually increased  to  three 
fourths  in  two  hours.  Then 
numbers  1,  2 — 4,  5  —  7,  8 
— 10,  11  are  lighted  in  the 
same  way.  Colour  will  be- 
gin to  show  inside  the  muffle 
about  the  fifth  or  sixth  hour, 
and  the  top  dampers  can 
come  out  a  little,  the  front 
one  more  than  the  back,  to 
draw  the  flame  towards  the 
door. 

When  the  eight  burners 
have  been  on  about  one 
and  one  half  hours  the  muffle 
will  probably  show  a  dull 
red  inside  and  all  danger  of  blowing  will  be 
passed.  Two  more  burners  at  three  fourths  may 
now  be  put  on  and  at  the  expiration  of  another  one 
and  one  half  hours  the  remaining  two  may  be  turned 


TlLf 
THIMBUS 


FIG.  48 


on.  If  the  pressure  weakens  and  the  flame  shortens, 
the  main  cock  should  be  turned  on.  Just  above 
the  base  of  each  chimney  is  a  small  hole  and  the 
flame  should  show  through  these  towards  the  finish. 
If  the  flame  flaps  out  of  the  chimney  tops,  it  is  so 
much  waste  and  it  should  be  checked  at  the  taps. 
The  dampers  can  come  right  out  towards  the  end, 
being  used  to  sweat  the  flame  to  the  front  if  the  back 
appears  to  come  up  too  fast. 

As  white  heat  approaches,  the  cones  should  be 
observed  occasionally.  They  turn  the  colour  of 
their  surroundings  when  about  to  topple  over  and 
as  the  first  begins  to  curl  the  trial  near  the  spy  can 
be  hooked  out  quickly  and  tested.  When  the  right 
cone  is  well  down,  the  main  cock  and  then  the  burner 
taps  are  turned  off.  The  air  regulators  are  now 
pulled  back  and  after  a  few  minutes  the  dampers 
are  closed.  The  metre  is  then  checked  and  entered 
in  the  firing  book. 

The  kiln  should  be  allowed  to  cool  slowly  for  at 
least  12  hours,  but  the  clamming  at  the  top  may 
come  away  and  this  will  expedite  the  cooling  with- 
out risk  to  the  muffle.  This  time  applies  to  a  muffle 
of  about  20"  x  15"  X  30"  dimensions.  A  smaller 
kiln  will  fire  up  and  cool  in  a  shorter  time. 

Gas  kilns  as  made  in  America  vary  in  the  arrange- 
ment of  their  burners,  but  the  principle  is  the  same. 
They  are  simple  to  manipulate  and  especially  handy 


103 

for  firing  "  on  "  decoration,  as  they  are  fitted  with 
shelves  and  uprights.  The  burners  once  alight, 
the  flame  is  gradually  increased,  but  where  the  press- 
ure is  uncertain,  it  is  well  to  keep  something  in 
reserve. 

Firing  with  oil  is  somewhat  different.  The  as- 
bestos fibre  in  the  pans  is  well  saturated  with 
kerosene,  the  tanks  filled,  and  the  taps  turned  off. 
A  light  is  applied  to  the  burners  and  when  both  are 
burning  freely  the  taps  are  turned  on  to  allow  a 
thin  stream  of  oil  to  flow  into  the  pans.  From  the 
merest  trickle  at  first,  the  flow  should  be  gradually 
increased  as  the  heat  develops.  This  is  observed 
through  the  mica  spy  hole  in  the  door  and  the  one 
above  tells  when  the  flame  is  reaching  its  maxi- 
mum. Should  it  flare  over  irregularly  before  the 
finish  it  means  that  the  combustion  is  not  per- 
fect and  there  is  danger  of  clogging.  The  supply 
of  oil  should  be  reduced  and  the  draught  regulated 
until  the  flame  in  the  combustion  chamber  burns 
clear. 

All  soot  or  carbon  forming  in  the  fire  box  should 
be  raked  out  and  the  oil  supply  checked,  as  it  indi- 
cates a  too  liberal  supply.  As  the  oil  in  the  tank 
subsides  it  should  be  refilled  and  the  taps  checked, 
as  the  increase  in  pressure  is  apt  to  vary  the  flow. 

The  later  patterns  of  oil  kilns  have  several  advant- 
ages over  the  kiln  described.  The  muffle  construe- 


104 

tion  and  the  burner  arrangements  are  ingenious  and 
practical,  and  need  little  manipulation  to  insure 
even  distribution  of  heat. 

The  oil  tanks  and  taps  will  need  attention  at 
each  firing,  otherwise  sediment  will  collect  and 
choke  the  even  flow  of  paraffin  oil  or  kerosene.  With 
both  gas  or  oil  kilns  the  amount  of  fuel  consumed 
should  be  recorded,  together  with  the  time,  weather 
conditions,  cones,  and  results  of  firing,  in  the  "  Kiln 
Log." 


IL 


FJ&E.BOX/ 
SKETCH  JIG 


OIL  KILN 
OF  GLAZED  POT/. 


A  SPY-HOLE          D  POT  OK 
JB  THRlECONt/    E  nOjo 

c  TQTWnfi  LEG/  F  POT/ 

OM  5HKED  JTILT.  ^  .men/-  G*icc  JTtCJ? 


FIG.  49 


CHAPTER  XI 

GLOST  FIRING 

"When  Fortune  bringeth  thee  affliction,  console  thyself 
by  remembering  that  one  day  thou  must  see  pros- 
perity, and  another  day  difficulty." 

—  From  EL  KORAN. 

THE  hard  porous  biscuit  shape  will  now  need  a 
coat  of  glaze  and  a  subsequent  glost  fire. 

Raw  glazes  for  green  shapes  are  now  seldom  used 
except  for  the  coarser  wares  or  peasant  pottery. 
In  commerce  it  is,  however,  largely  used  on  tiles, 
mouldings,  and  big  sanitary  appliances.  For  com- 
mon cheap  crockery  a  soft  lead  glaze,  often  galena, 
is  generally  used.  It  is  applied  with  a  brush,  or 
the  pot  still  leathery  and  tough  is  dipped  in  the 
glaze.  Raw  glazes  have  a  strong  inclination  to 
leave  in  the  firing.  They  are  very  difficult  to 
manipulate  unless  they  are  of  the  simplest  formula 
and  fired  very  slowly.  The  addition  of  a  little  clay 
in  the  form  of  slip  to  the  glaze  will  often  counteract 
the  tendency  to  leave  the  pot. 

The  ordinary  glazes  in  dry  powder  form  are  mixed 
with  water  to  the  consistency  of  cream  and  passed 
with  the  aid  of  a  stout  brush  through  a  phosphor 

107 


108 

bronze  sieve  into  a  large  basin  or  tub.  The  sieves 
may  range  from  eighty  to  two  hundred  mesh,  accord- 
ing to  the  delicacy  of  the  work.  For  ordinary 
work  No.  100  suffices.  The  biscuit  to  receive  the 
glaze  should  be  quite  clean  and  free  from  dust  or 
dirt  with  the  insides  carefully  dusted  or  blown  out. 
Grease  will  stop  absorption,  but  with  opaque  glazes 
discoloration  is  not  of  great  importance.  If  the 
biscuit  is  hard  and  inclined  to  be  non-porous,  the 
glaze  will  need  to  be  mixed  fairly  thick  before  it 
will  cling;  with  soft  and  porous  shapes  a  com- 
paratively thin  mixture  will  take  readily. 

No  immutable  law  can  be  laid  down  for  the  exact 
thickness  of  the  coat  of  glaze.  All  glazes  vary.  One 
sixteenth  inch  may  be  enough  for  one  and  far  too  thin 
for  another.  From  one  twentieth  inch  for  thin  trans- 
parent glaze  to  one  eighth,  inch  for  matts  is  a 
fair  average.  It  is  well  to  err  on  the  thick  side  to 
avoid  an  impoverished  look.  Trials  on  odd  pieces 
of  biscuit  fired  in  horizontal  and  vertical  positions 
will  best  settle  the  point. 

In  all  cases  the  inside  is  first  half  filled  with  glaze 
which  is  rolled  quickly  round  and  out.  The  deposit 
is  then  tested  with  a  knife.  The  glaze  for  the  inside 
should  be  slightly  thinner  in  composition  than  for 
the  outside,  as  it  is  inclined  to  pool  in  the  bottom 
if  too  thick.  The  outside  and  the  neck  are  then 
scraped  free  of  all  splashes. 


109 


POUKINC 


FIG.  50 


110 

To  glaze  the  outside  of  the  pot  the  methods 
employed  are  painting,  spraying,  dipping,  and  pour- 
ing. In  painting,  two  or  three  coats  applied  with 
a  flat  soft  brush  may  be  necessary.  In  spraying,  the 
glaze  is  thinned  considerably  and  blown  through  a 
vaporizer  by  means  of  a  foot  pump.  (Fig.  51.) 
The  shape,  its  mouth  closed  with  a  small  bowl  or 
saucer,  is  placed  on  a  whirler  in  a  draught  box  and 
slowly  revolved.  The  draught  draws  the  waste 
spray  away  from  the  operator,  who  should  wear  a 
respirator.  This  method  is  excellent  where  any 
gradation  is  required.  It  is  easily  learned.  Un- 
fortunately, it  requires  expensive  apparatus  to  ren- 
„  der  it  safe  with  lead  glazes.  Unless  it  is  done  on  a 
big  scale  and  the  waste  glaze  retained,  it  is  also 
wasteful. 

In  dipping,  the  pot  is  plunged  right  under  in  a 
tub  of  glaze  which  is  kept  well  stirred  to  prevent 
the  heavy  constituents  settling.  (Figs.  52  and  53.) 
This  requires  considerable  dexterity.  In  a  school, 
glaze  is  seldom  mixed  in  sufficient  quantities  to  per- 
mit of  this  being  acquired. 

Perhaps  the  most  satisfactory  method  is  pouring. 
(Fig.  50.)  The  shape  is  reversed  and  stood  upon  a  big 
stilt  or  two  strips  of  wood  over  a  bowl  or  tub.  Then 
the  glaze  is  poured  from  a  jug  round  the  edge  of  the 
base,  until  every  part  is  covered.  With  a  little 
practice  a  quite  even  coat  can  be  thus  applied. 


Ill 


yp  LAYING 


FIG.  51 

Owing  to  the  inversion  of  the  shape  it  is  slightly 
thicker  at  the  shoulder  and  neck,  an  excellent  point 
in  glazing.  When  dry,  the  base  is  scraped  and 
wiped  clean  with  a  sponge  and  the  lip  touched  up 
with  a  brush. 

With  matt  glazes,  as  has  been  noted,  a  thick  coat 
is  necessary.  If  very  porous,  the  shape  may  be 
soaked  first  in  clean  water  to  take  some  of  the  suction 
out  of  the  biscuit.  When  glazed,  it  is  essential  that 
all  dips  and  inequalities  be  removed.  If  thinly 
coated,  the  glaze  will  assume  a  glossy  surface  when 
fired. 


PIPPING. 


FIG.  52 

Whatever  process  is  used,  the  lip  and  base  of  a 
pot  should  receive  careful  attention,  the  rims  es- 
pecially should  be  thickly  and  evenly  coated  with 
glaze.  The  thickness  can  be  tested  with  the  point 
of  a  knife  and  any  scratches  or  bare  spots  should  be 
filled  in  and  rubbed  flat  as  they  are  apt  to  show  at  the 
finish  if  the  glaze  is  at  all  refractory.  Never  starve 
the  glaze,  for  a  thin  coat  imparts  a  poor  cheap  look  to 
any  pot  that  is  seldom  remedied  with  entire  success. 

When  only  one  kind  of  glaze  is  used,  the  application 
is  quickly  learned.  With  hard  and  soft,  lead  and 
leadless  glazes,  both  opaque  and  transparent,  and 
possibly  a  combination  of  spraying,  painting,  and 
pouring,  the  difficulties  are  greatly  increased.  Prac- 
tical experience  will  be  the  only  safe  guide.  But 
speaking  generally,  a  sprayed  coat  can  be  thicker  than 


113 


DIPPING 


a  poured  coat.  Hard  glazes  give  less  trouble  than 
soft  if  too  liberally  applied.  Tin  glazes  will  stand  a 
lot  of  over-firing  even  when  thin  and  the  reverse 
holds  good  of  matt  glazes.  Raw  borax  glazes 
require  much  more  careful  firing  than  raw  lead  glazes 
but  often  give  better  colour  results  and  are  less 
liable  to  sulphuring. 

When  glazing  with  a  transparent  glaze  over  under- 
glaze  painting  a  thin  coat  is 
advisable.  If  it  be  thick  and 
run,  the  painting  is  spoiled ; 
but  if,  after  firing,  it  appears 
thin,  another  light  spray  may 
be  tried.  But  whole  chap- 
ters of  writing  will  never 
settle  these  points.  Re- 
peated trials  on  odd  pieces 
of  biscuit  will  elucidate  more 
than  many  books.  In  pack- 
ing a  glost  or  glaze  kiln  stilts  and  spurs  instead  of 
saddles  must  be  used  to  prevent  the  pots  from  stick- 
ing to  the  floor  or  shelves.  (Figs.  49  and  54.)  For  the 
same  reason  the  pots  must  not  touch  each  other.  With 
glazes  requiring  a  high  temperature  the  space  between 
pots  of  different  colour  should  be  considerable.  An 
appreciable  amount  of  glaze  is  liberated  in  the  in- 
tense heat  and  a  blue  pot  will  often  leave  a  distinct 
blue  patch  on  any  light  pot  placed  too  near.  Soft 


FIG.  53 


114 


ao<^)^ 

THIMBU*  5ocKET  •  EGG  STILT  •  CONE-BITS 


FIG.  54 

glazes  liable  to  run  or  drip  should  be  placed  on 
separate  bats  well  flinted  beneath.  Any  crack  in 
the  muffle  should  be  well  stopped  and  lime  may  be 
used  to  neutralize  the  effects  of  any  sulphur  that  may 
enter. 

As  the  back  is  usually  hotter  than  the  front  the 
hard  glazes  should  be  packed  first,  and  by  selecting 
suitable  shapes  a  good  setter  will  pack  a  surprising 
amount  into  even  a  small  kiln.  The  clamming 
should  be  done  with  care,  as  bits  are  liable  to  flake 
off  and  stick  to  the  glaze.  The  top  plug  only  need 
be  left  out  and  the  lighting  up  proceeded  with  as 
before. 

The  gradual  increase  of  heat  is  very  essential  in 
firing  glaze,  for  any  sudden  jump  or  reduction  will 
play  all  manner  of  games  in  a  glost  oven.  The 


115 

slow  start  is  not  so  important,  there  being  no  risk  of 
blowing.  Indeed  the  glaze  is  best  in  a  sharp  quick  fire. 

Although  cones  should  always  be  used  and  are 
excellent  indicators,  experience  will  soon  show  when  a 
kiln  is  fired  up.  It  may  be  advisable  to  go  on  a  little 
after  the  cone  is  over  until  all  looks  fluxed  so  as  to  get 
rid  of  bubbles.  These  appear  in  some  glazes  until 
the  last.  They  do  not  always  go  down  on  cooling, 
but  those  glazes  that  bubble  through  over-firing 
should  be  avoided.  Possibly  the  trouble  will  arise 
from  sulphur  in  the  body  which  must  be  corrected. 
Trials  are  always  useful  but  they  must  be  small  and 
easily  hooked  out,  as  constant  poking  about  at  the 
spy  hole  lowers  the  temperature  of  the  muffle  at 
the  front,  just  where  it  is  most  difficult  to  get  it  up. 

When  fired,  a  glost  kiln  should  cool  very  slowly, 
for  any  sudden  access  of  cold  air  is  liable  to  stunt 
or  crack  the  pots.  When  firing  over  glaze  decoration 
where  the  glaze  does  not  run,  the  packing  is  much 
simplified.  With  low-firing  lustres  the  pots  may 
even  touch  each  other. 

All  this  has  been  set  out  at  great  length  but  we 
shall  find  over  and  above  this  that  each  kiln  has  its 
own  little  ways  which  must  be  studied  and  hu- 
moured before  the  best  results  can  be  obtained. 

The  chief  thing  to  avoid  is  a  sudden  flush  or  jump 
in  the  heat.  The  main  thing  to  aim  at  is  a  slow  start 
steadily  increasing  to  a  sharp  finish.  The  state  of 


116 

the  muffle,  a  dry  or  a  damp  day,  will  modify  each 
firing  a  little,  but  the  above  generalization  will  have 
a  fairly  wide  application  to  the  working  of  a  small 
kiln. 

Unpacking  is  a  compound  of  despair  and  delight, 
and  is  best  done  slowly.  As  the  colour  dies  the  clam- 
ming, if  any,  may  be  knocked  away,  and  later  on  the 
spy  plugs  removed.  When  comparatively  cold,  the 
door  may  be  opened  slightly,  and  left  so  for  one  or 
two  hours.  Then  the  front  pots  can  be  extracted 
but  those  at  the  back  should  be  allowed  another  half 
hour.  Be  very  careful  of  the  razor  edges  of  broken 
stilts  or  glaze  dips.  A  steel  chisel  should  be  used  for 
chopping  rough  edges  or  removing  refractory  stilts. 
If  necessary  the  bases  may  be  ground  on  an  emery 
wheel  until  the  pot  stands  true. 


CHAPTER  XII 

GLAZES  AND  LUSTRES 

"I  began  to  think  that  if  I  should  discover  how  to  make 
enamels  I  could  make  earthen  vessels  and  other  things 
very  prettily,  because  God  had  gifted  me  with  some 
knowledge  of  drawing."  —  PALISSY. 

IT  is  in  this  department  of  potting,  with  its  sur- 
prises, difficulties,  and  disappointments,  its  rare  but 
exciting  successes,  that  for  most  potters  the  greatest 
interest  lies.  To  those  of  a  scientific  bent  it  is  per- 
haps the  summit  of  the  craft,  but  the  artist  groping 
amidst  formulas  and  methods  may  take  heart.  The 
finest  work  in  pottery  was  not  produced  by  scientists 
alone  and  does  not  depend  altogether  upon  the 
quality  of  its  paste,  its  unique  colour,  or  strange 
lustre.  The  last  word,  the  form,  decoration,  and 
craftsmanship,  is  with  the  artist. 

It  is  beyond  the  scope  of  a  book  of  this  description 
to  enter  into  a  necessarily  long  and  complicated 
account  of  the  different  processes  concerned  in  the 
composition  of  glazes.  It  will  be  sufficient  to  indi- 
cate their  leading  characteristics  plainly  enough  to 
enable  the  student  to  start  experimenting.  None 

117 


118 

can  afford  to  miss  opportunities  for  experiment, 
just  as  surely  as  none  can  afford  to  be  always  ex- 
perimenting. For  a  full  description  of  materials 
and  glazes  and  their  manufacture  such  books  as 
those  of  Drs.  Shaw,  Furnival,  and  Hainbach  are 
recommended. 

Putting  aside  salt  glaze  we  find  a  countless  number 
of  both  lead  and  leadless  glazes.  They  range  from 
the  thin  silicious  coating  of  the  ancients  up  to  the  rich 
alkaline  glazes  of  the  Persians  and  Chinese;  from 
the  raw  galena  of  peasant  pottery  to  the  rich  Majoli- 
cas and  fine  hard  glazes  of  modern  commerce. 
Salt  glaze  is  obtained  by  the  vaporizing  of  salt  inside 
the  kiln  at  a  great  heat.  The  sodium  oxide  so 
formed  combines  with  the  silicates  in  the  clay  to 
form  a  very  thin  coat  of  refractory  glass,  intimately 
connected  with  the  body.  Porcelain  glazes,  though 
not  differing  so  much  in  composition  from  the  or- 
dinary fine  earthenware  glazes,  are  extremely  hard, 
being  compounded  of  kaolin,  felspar,  and  quartz, 
with  possibly  limestone  and  ground  sherds.  It 
has  in  common  with  the  salt  glaze  the  close  union 
with  the  body,  so  that  when  fractured  the  line 
of  demarcation  between  glaze  and  body  is  indeter- 
minable. 

With  a  few  minor  exceptions  the  following  list 
comprises  the  ingredients  of  all  colourless  glazes: 


119 

Kaolin  Barytes  White  lead 

Quartz  Bismuth  Red  lead 

Cornish  stone  Gypsum  Zinc  oxide 

Felspar  Limestone  Tin  oxide 

Fluorspar  Nitre  Salt 

Flint  Borax  Soda 

Sand  Bone  ash  Potash 

These  materials  must  be  free  from  all  trace  of  iron. 
They  are  pulverized  and  some  are  calcined  or  oxi- 
dized. Then  they  are  mixed  in  varying  quantities 
to  form  the  glaze  mass.  This  mass  is  easily  fusible 
when  lead  or  borax  is  present  in  large  proportions, 
more  infusible  or  harder  the  more  silica  it  contains, 
and  very  refractory  if  alumina  is  present  in  any 
quantity.  The  silica  forming  the  glassy  part  of  the 
glaze  is  stiffened  by  the  presence  of  alumina,  which 
stops  any  tendency  to  run. 

Lead  is  very  largely  used  as  a  powerful  flux  at 
low  temperatures  but  is  unsuited  to  hard  glazes. 
Borax  and  boracic  acid  are  important  constituents 
of  leadless  glazes.  They  are  used  to  replace  some  of 
the  silica,  than  which  they  are  more  fusible.  Matt 
or  non-reflective  glazes  are  opaque  and  less  vitreous 
than  the  glassy  glazes.  They  do  not  flux  or  run. 

All  these  minerals  are  finely  ground  before  mixing. 
Then  those  insoluble  are  mixed  and  fritted ;  that  is, 
fused  in  a  crucible  or  fritting  furnace  to  a  greater  or 
less  degree,  according  to  the  hardness  of  the  glaze.  If 


120 

fused  into  a  glass,  the  melted  mass  is  poured  into 
water  to  facilitate  the  next  process,  which  is  its  re- 
duction to  a  fine  powder  by  re-grinding.  Then  the 
completing  ingredients  are  added  and  the  mass 
coloured  by  the  addition  of  metallic  oxides.  Of  these 
the  chief  are : 

Iron  Nickel  Cobalt  Manganese 

Copper          Antimony          Chrome          Titanium 

and  the  more  precious  metals,  in  various  forms, 
as  oxides,  carbonates,  sulphates,  and  nitrates  soluble 
in  the  glaze  at  great  heat. 

These  metals  impart  the  many  varied  colours 
found  in  pottery.  Zinc  oxide  is  used  to  brighten  a 
glaze  or  to  stabilize  colour.  Tin  oxide,  which  is 
insoluble  at  great  heat  but  remains  in  suspension, 
gives  opacity. 

This  is  no  more  than  a  skeleton  outline  of  the  in- 
tricate processes  often  used  in  the  fabrication  of 
a  glaze.  The  manifold  minerals,  metals,  oxides, 
acids,  and  alkalies  are  used  in  a  variety  of  ways  by 
the  modern  chemical  potter. 

To  all  this  seeming  complication  is  added  the  ques- 
tion of  pastes  and  bodies.  There  then  arises  the 
great  problem  of  fitting  one  to  the  other.  Salt  glaze 
and  porcelain  excepted,  the  finished  pot  presents 
three  stratas.  Outside  is  the  glaze,  next  the  body, 
then  inside  the  glaze  again.  If  the  coefficient  of 
expansion  of  these  three  layers  differs,  in  other 


words,  if  the  glaze  does  not  fit,  the  result  is  crazing, 
that  bugbear  of  the  potter. 

This  crazing,  which  has  been  followed  up  and  de- 
veloped into  their  delightful  crackle  by  the  Chinese, 
may  show  itself  at  once  or  only  after  a  lapse  of 
months.  It  appears  as  a  minute  network  of  fine 
cracks  over  the  entire  surface  of  the  pot.  It  is  often 
not  unsightly,  but  sooner  or  later  it  must  cause 
devitrification.  The  glaze  after  a  time  assumes  an 
evanescent  iridescence  followed  by  a  dull  smoky 
appearance;  finally,  perhaps  not  for  many  years, 
it  decomposes  and  peels  off. 

With  low-firing  natural  clays  rich  in  silica  and  iron, 
the  craze  is  not  of  much  consequence.  The  body  it- 
self at  a  moderately  high  temperature  becomes  non- 
porous.  With  hard  short  bodies  containing  lime 
or  chalk  it  may  have  quite  disastrous  consequences. 
Water  placed  inside  will  eventually  percolate 
through  leaving  a  network  of  grey  lines  all  over  the 
pot  and  completely  spoiling  its  appearance. 

It  will  be  readily  granted  that,  whether  porous 
or  non-porous,  a  craze  is  most  undesirable  on  any 
piece  of  pottery  that  may  be  used  for  food  or  drink. 

It  is  here  that  the  commercial  potter  is  such  an 
admirable  fellow.  Many  of  the  glazes  on  modern 
tablewares  are  perfect  for  their  purposes.  Some- 
times only  a  little  more  fire  is  needed  to  stop  the 
nuisance,  but  a  bad  craze  usually  needs  more  atten- 


122 

tion.  The  glaze  requires  stiffening,  and  the  addition 
of  ground  flint  or  quartz,  China  stone  or  clay  and 
felspar  introduces  alumina  and  silica  and  raises  the 
fusing  point.  The  substitution  of  borax  for  a  portion 
of  the  silica  can  also  be  tried  and  will  permit  the  use 
of  slightly  lower  firing  point. 

If  the  glazes  are  bought  ready  mixed,  the  body  must 
be  altered  instead.  Refractory  China  clays  should  be 
replaced  by  more  fusible  clays  or  some  reduction 
made  in  the  amount  of  infusible  materials.  The 
addition  of  ground  sherds  or  flint  will  have  a  contrary 
effect  should  the  glaze  peel  or  crack  at  the  edges,  as 
it  may  do  on  a  very  silicious  body.  In  working 
with  natural  clays  on  a  moderate  scale  it  will  be 
found  best  to  mix  "fat"  or  rich  natural  clays  with 
those  of  a  more  porous  or  hard  nature.  A  few 
graded  mixtures  submitted  to  a  thorough  trial  should 
soon  show  when  a  sympathy  has  been  established 
between  the  body  and  glaze. 

The  receipts  given  on  pages  183  and  184  will  make 
good  colourless  glazes  without  fritting  if  thoroughly 
ground  in  a  mortar  and  passed  through  a  sieve.  Num- 
bers 3  and  7,  when  calcined,  will  give  much  more  even 
results  and  they  can  be  coloured  by  the  addition  of  the 
oxides  named.  But  simple  as  it  sounds,  the  washing, 
grinding,  fritting,  re-grinding,  and  sieving  is  a  long 
and  laborious  process  demanding  machinery,  and  on 
that  account  is  unsuited  to  schools  or  potters  of  mod- 


123 

erate  means.  Glazes  like  Nos.  1  and  2  will  do  quite 
well  for  elementary  work  but  unless  the  appliances 
are  to  hand  the  manufactured  article  will  have  to 
be  relied  on  for  more  finished  and  ambitious  work. 

If,  indeed,  you  are  already  in  possession  of  a  good 
receipt  for  a  fine  colour  and  glaze,  one  quite  worth 
while,  so  much  the  better.  Mix  it  and  feel  the  joy 
of  the  Compleat  Potter  unafraid  of  spoiling  his  own 
good  shapes  with  a  faulty  or  unknown  glaze. 

Admittedly,  to  get  anywhere  in  an  original  direc- 
tion systematic  research  is  essential.  One  must  keep 
on  experimenting,  keep  on  hoping,  and  keep  on  taking 
notes ;  but  at  the  start  let  us  not  be  too  impatient 
or  independent  if  we  wish  to  produce  good  pots. 

There  is  often  among  young  potters  a  false  pride 
that  prevents  them  using,  and  among  old  potters 
acknowledging  the  use  of,  the  manufactured  article. 
Why  this  should  be  is  a  little  difficult  to  understand. 
A  painter  might  far  more  reasonably  be  ashamed  to 
use  modern  tube  colours  or  a  stained-glass  craftsman 
as  logically  insist  on  making  his  own  glass,  as  a 
potter  in  the  twentieth  century  refuse  to  avail  him- 
self of  the  wonderful  range  of  glazes  that  modern 
research  has  placed  at  his  disposal.  These  resources 
should  be  used  intelligently,  not  mechanically,  or  by 
the  book  —  artistically,  inventively,  secretly,  if  you 
will,  but  they  should  be  used  —  until  the  multitudi- 
nous experiments  have  borne  fruit  and  repeated  trials 


124 

convince  you  that  at  last  you  possess  some  gem  of 
research  worth,  as  well  it  may  be,  the  months  of 
patient  toil  engendered  in  its  production. 

The  various  receipts  are  given  on  pages  183  and  184 
without  analysis  of  the  composition  of  the  paste  or 
body  to  which  they  were  applied.  The  first  group 
have  been  used  on  common  earthenware  clays  with 
complete  satisfaction.  They  are  to  be  considered  as 
points  of  departure  for  future  experiments  in  which 
they  may  be  modified  at  will,  and  not  regarded  as  a 
contribution  to  the  science  of  glaze  making. 

In  colouring  it  will  be  found  that  combinations 
of  cobalt,  iron,  and  copper  oxides  give  an  interesting 
range  of  simple  blues  or  greens ;  iron  and  manganese 
browns ;  and  so  forth.  The  colour  mass  or  stain  is 
ground  fine  and  lawned,  and  from  about  2  to  7  per 
cent  mixed  with  the  colourless  glaze  mass,  according 
to  the  depth  of  colour  required.  The  ordinary 
under-glaze  colours  may  be  used  to  stain  glazes,  the 
percentage  being  fixed  by  small  trials.  For  the  rare 
colours  —  turquoise,  crimson,  or  purple  —  a  more 
complicated  process  is  necessary  and  only  perfected 
after  many  trials.  The  ingredients  of  these  fine 
colours  are  naturally  kept  secret  by  their  fortunate 
possessors. 

It  must  be  noted  that  a  glaze  suited  to  one  body 
may  peel  or  run  off  an  unsuitable  one.  Then 
a  colourant  is  affected  differently  by  a  lead  or 


125 

an  alkaline  base  in  the  glaze.  Again,  copper  and 
iron  oxides  may  help  to  flux  a  glaze,  whilst  cobalt 
or  nickel  will  exert  a  contrary  effect.  Cobalt,  being 
a  strong  colourant,  will  need  a  sparing  use,  whereas 
a  similar  percentage  of  iron  will  merely  tinge  the 
glaze  mass.  And  so  ad  infinitum. 

It  is  self-evident  that  any  attempt  to  emulate  the 
vast  range  of  the  modern  ceramic  chemist  is  doomed 
to  failure.  To  a  craftsman  the  fabrication  of  one 
fine  individual  glaze  or  lustre  is  an  achievement  of 
which  he  may  be  proud,  and  for  which  he  will  find 
abundant  and  varied  uses.  In  this  connection  it  is 
encouraging  to  the  craftsman  to  learn  from  so  high 
an  authority  as  W.  Burton,  Esq.,  F.C.S.,  that  it  is 
impossible  to  obtain  with  purified  oxides  the  fine 
tones  got  by  the  Orientals  with  impure  materials. 
Further,  that  the  simple  glaze  of  the  Persians  —  a 
mixture  of  clean  white  sand  with  soda  or  wood  ash 
or  potash  —  is  still  the  best  for  under-glaze  painting. 
Although  tastes  differ  so  widely,  invariably  it  will 
be  found  that  more  and  more  heat  will  be  the  cry. 
Imperceptibly  this  leads  to  the  desire  for  hard,  cold, 
"fat"  translucent  glazes,  neither  matt  nor  glossy. 
And  on  the  summit,  far  out  of  reach,  stand  the 
wonders  of  the  Old  Chinese. 


126 


LUSTRES 

There  are  several  kinds  of  lustres,  but  the  true 
lustres  possess  a  pearly  iridescence  in  addition  to 
their  colour.  The  copper  and  silver  lustres  of  the 
eighteenth-century  Staffordshire  potters  were  thin 
metallic  films  over  the  whole  surface  of  the  glaze. 
Gold  or  silver  solutions  were  used.  Only  where  the 
gold  was  fired  on  a  white  clay  is  there  any  iridescence, 
and  then  hardly  so  pronounced  as  to  deserve  the  name 
of  lustre.  The  bismuth  and  other  lustres  made  by 
the  modem  potter  are  combinations  of  metallic  oxides 
and  resinates  dissolved  in  ethereal  oils.  These  are 
painted  on  the  glaze,  transparent  or  opaque,  but 
having  almost  invariably  a  lead  base,  and  then  fired 
at  a  dull-red  heat.  The  medium  disappears,  and  the 
metal  in  a  finely  divided  state  is  deposited  on  the 
surface  of  the  glaze.  This,  however,  gives  a  painted 
look  very  different  from  the  lovely  irradiance  of  the 
Persian  Hispano-Mooresque  or  Italian  work. 

With  these  the  lustres  were  fired  in  a  reducing  at- 
mosphere, one  supercharged  with  combustible  gases, 
the  metals  decomposed  and  fixed  to  the  semifluxed 
glaze.  The  manipulation  was  not  infallible  and  was 
attended  with  much  risk ;  but  the  successful  pieces 
are  unrivalled,  and  according  to  Piccolpasso  "paid 
in  gold."  De  Morgan,  who  more  nearly  approached 
the  works  of  the  Italian  masters  than  any  other 


127 

modern  potter,  used  a  very  similar  medium  and 
method  with  his  fine  lustres.  In  the  last  few 
years  lustres  have  been  brought  to  such  perfec- 
tion, in  preparation,  application,  and  firing,  that 
accident  is  practically  eliminated.  Glorious  colours 
and  gorgeous  effects  are  obtained.  Yet  it  may  be 
said  without  senseless  adulation  of  the  merely  medi- 
aeval that  nothing  has  been  produced  superior,  or 
even  akin  in  spirit,  to  the  work  sent  out  from  Persia, 
Spain,  or  the  botega  of  the  inimitable  Maestro 
Georgio  of  Gubbio. 

Lustres  may  be  bought  ready  to  apply.  They 
are  then  painted  on  the  glazed  pot,  which  is  re-fired 
at  a  dull-red  heat  in  the  ordinary  oxidizing  atmos- 
phere. Once  the  painted  look  has  been  contrasted 
with  the  lustrous  appearance  of  the  reduced  effects 
there  is  only  one  kind  of  lustre  for  the  artist.  For- 
tunately, perhaps,  their  preparation  is  not  easy,  and 
the  correct  method  of  reducing  is  a  difficulty  to  be 
overcome  by  practical  experiment  alone.  Hainbach 
gives  many  practical  receipts  for  lustres  that  are  not 
beyond  the  scope  of  a  craftsman.  The  reducing  at- 
mosphere can  be  obtained  in  an  open  kiln  by  the  in- 
troduction at  the  right  moment  of  any  combustible 
giving  smoke  free  from  all  traces  of  sulphur. 

In  firing  with  a  muffle  kiln  the  introduction 
of  coal-gas  free  from  sulphur  is  a  matter  at- 
tended with  some  risk  at  the  necessarily  low  tern- 


128 

peratures  required  by  the  lustres.  It  should  be 
approached  with  caution,  and  each  mixture  will  have 
a  varied  firing  point,  the  correctness  of  which  is 
established  only  by  trials. 

Lustres  applied  with  skill  and  restraint  enhance 
the  most  beautiful  glaze,  but  in  unskilled  hands 
they  inevitably  vulgarize  and  cheapen.  The  fresh, 
unsophisticated  renderings  of  the  Persians  or  the 
Moors  and  the  virility  of  the  Italians  should  be 
studied,  but  not  merely  imitated  before  working  in 
this  medium. 


^  PAINTING  OUTHT 


FIG.  55 


CHAPTER  XIII 

DECORATION 

"The  world  is  still  deceiv'd  with  ornament." 

—  Merchant  of  Venice. 

DECORATION  has  been  touched  upon  briefly  in 
one  or  two  of  the  preceding  chapters.  To  attempt  a 
description  of  the  various  kinds  of  decoration  which 
it  is  possible  to  place  on  a  pot,  another  book  would  be 
needed.  Their  name  is  legion.  They  range  from 
the  simple  and  entirely  satisfactory  work  of  primitive 
and  peasant  peoples  to  the  wonderful  enamel  decora- 
tions of  the  Chinese.  With  such  an  enormous  field 
and  varied  choice  it  is  difficult  to  particularize  and 
foolish  to  dogmatize.  The  hints  below  are  intended 

K  129 


130 

but  to  stimulate  interest  in  the  at  present  unex- 
plored fields  that  lie  beyond  the  beaten  track. 

Any  representative  collection  of  ceramics  will 
prove  a  veritable  treasure  house  of  suggestion  to 
the  student.  All  will  be  there.  The  difficulty  is  to 
choose,  and  choose  aright.  The  bold  brushwork  of 
Cyprus  foils  the  marvellous  families  vert  and  rose 
of  the  Chinese,  the  faultless  Wedgwood  sets  off 
the  virile  Toft.  One  sees  how  the  Italians,  with 
almost  crude  colours,  —  blue,  green,  red,  yellow, — 
developed  their  wonderfully  robust  school  of  figure 
painters;  then  their  fanciful  arabesques  are  prolific 
of  ideas.  The  Greek  style  —  red  and  black  and 
white  —  is  a  rich  field  waiting  for  the  reaper.  The 
peerless  Persian  pots,  the  plaques  from  Spain,  the 
steins  and  stoves  from  Germany,  the  fresh  Delft 
wares ;  these  and  many  others  crowd  round  for  rec- 
ognition and  disconcert  the  choice. 

But  having  come  so  far,  let  us  not  choose  the  horrific 
style  that  models  most  faithfully  a  cabbage,  tops  it 
with  a  lifelike  snail  as  handle,  and  cunningly  converts 
the  whole  into  a  vegetable  dish  !  .  .  .  (in  S.  K.  M .). 
Nothing  should  be  more  distressing  to  the  artist 
than  to  see  great  skill  and  craft  thus  misapplied. 
Yet  how  often  does  the  search  after  false  originality 
lead  only  to  meretricious  cleverness  or  vulgarity, 
which  creeps  in  unseen  during  the  too  close  struggle 
with  the  craft. 


131 

But  our  muttons  need  tending.  Broadly  speaking, 
all  decoration  falls  under  three  heads  :  Glaze ;  Relief ; 
Painting ;  —  subdivided  into  many  combinations  of 
these  three  classes. 

The  application  of  glaze  has  already  been  de- 
scribed. A  pot  possessing  a  noble  form  and  glaze  is 
obviously  in  no  need  of  decoration;  no  artist  would 
attempt  it.  The  Chinese  and  Japanese  are  safe 
guides  here.  Their  rich  glazes  and  fine  forms 
are  set  off  in  the  simplest  and  most  effective  manner. 
This  is  potting,  pure  and  simple. 

Under  relief,  we  group  all  modelling,  —  raised  or 
sunk,  embossments,  flutings,  mouldings,  feet,  handles, 
or  applied  figures.  At  one  extreme  come  the 
earliest  attempts  at  decoration  in  slip  or  clay,  highly 
developed  in  the  Gallo-  and  Egypto-Roman  and 
Romano-British  wares.  The  matured  slip  must  be 
applied  fairly  thick  to  the  still  moist  pot  and  then 
dried  slowly.  Any  work  applied  to  dry  shapes  is 
liable  to  crack  in  drying  or  leave  in  firing.  Probably 
the  most  effective  use  of  slip  is  seen  in  the  old  tygs 
and  dishes  of  Toft  and  others  of  his  time. 

The  simple  spotting  and  surfacing  has  been  carried 
to  perfection  by  the  Martin  Brothers,  who  have 
drawn  largely  upon  the  vegetable  world  for  their  in- 
spiration. Roman  Aretine  ware  shows  finely  exe- 
cuted reliefs  of  foliage  and  figures.  The  enrichment 
was  probably  worked  on  the  original  shape,  a  mould 


132 

was  then  taken,  and  the  vessel  pressed.  (See  chapter 
on  Casting.) 

Wedgwood  carried  this  method  still  further  (too 
far,  maybe)  and  used  different  coloured  bodies. 
The  reliefs,  so  finely  modelled  by  Flaxman,  were  fired, 
and  from  them  moulds  of  a  very  refractory  clay  were 
made,  called  pitcher  moulds.  The  reliefs  were  then 
pressed  and  affixed  to  the  vase,  and  the  whole  touched 
up  by  a  skilled  craftsman.  A  naive  and  unpreten- 
tious form  of  this  decoration  is  seen  in  the  stoneware 
and  salt-glazed  pottery  of  the  eighteenth-century 
English  potters  and  the  jolly  BeUarmines  of  earlier 
times.  Small  dies  were  used  in  the  Orion  ware, 
the  pattern  being  stamped  into  the  clay.  German 
stoneware  and  the  Ores  of  Flanders  show  sunk  and 
relief  patterns.  Between  the  two  extremes  lies  a 
rare  choice  of  style. 

This  method  of  using  patterns  lends  itself  par- 
ticularly to  fine  commercial  work  when  used  with  the 
restraint  seen  in  the  best  of  the  above-mentioned 
styles.  To  the  craftsman  it  offers  a  welcome  chance 
to  enlarge  his  production,  but  he  must  be  well 
equipped.  It  is  easy  to  acquire  the  mere  mechanism 
of  commerce  without  its  splendid  technique.  Finally, 
the  further  the  relief  is  developed  the  less  will  be  the 
appeal  of  form  and  the  less  the  possibilities  of  glaze. 

The  next  division  is  painting. 

It  is  in  this  branch  of  ceramic  decoration  that  the 


133 

widest  choice  lies.  The  scale  ascends  from  the 
simple  earthy  colourants  applied  to  the  unglazed 
pot  in  the  manner  of  the  American  Indian  up  to 
the  splendid  enamels  of  China  and  the  sumptuous 
but  sterile  wonders  of  —  shall  we  say  —  Sevres  or 
Worcester.  Much  of  the  modern  eighteenth-  and 
nineteenth-century  work  is  such  a  technical  tour  de 
force  that  one  hesitates  to  criticise  it.  But  careful 
scrutiny  will  often  show  that  the  artistic  difficulties 
have  been  undermined  rather  than  overcome.  Thus 
the  frank  frontal  attack  of  the  Persians  on  their 
absorbent  ground  or  of  the  potters  of  Delft  on  their 
unfired  tin  glaze  is  never  attempted,  and  probably 
never  can  be  attempted  in  the  factory  of  to-day. 

The  modern  method  of  painting  in  fat  oils  on  a 
prepared  ground  induces  in  any  but  the  most  ac- 
complished a  cramped  and  finnicky  style.  The  best 
and  really  most  beautiful  results  are  seen  in  the 
delicate  vertu  of  the  eighteenth  century.  Snuff 
boxes  and  ladies'  knick-knacks  ^exhibit  the  loveliest 
miniatures  in  an  impressible  medium.  How  far  it 
is  desirable  to  decorate  pots  with  such  pictures 
depends  on  the  sophistry  of  the  craftsman.  (For, 
ever  since  painters  were  pampered  by  princes  each 
erstwhile  honest  craftsman  must  needs  try  to  turn 
painter !) 

The  Chinese  who  laboured  with  infinite  patience 
upon  their  pots  still  seemed  to  preserve  a  spirit 


134 

lacking  in  the  works  of  their  western  imitators,  and 
their  avoidance  of  realism  saved  them  from  the 
many  pitfalls  that  yawned  for  the  Occidental. 

The  manner  in  which  the  Persians  and  Dutch 
preserved  their  freshness  has  been  noticed  already, 
but  the  encountering  and  surmounting  of  similar 
difficulties  is  at  the  bottom  of  most  successes.  A 
few  of  the  methods  of  painting  pots  are  here  set  forth, 
with  some  odd  variants. 

The  colourants  described  under  Glazes  are  also 
used  for  painting.  Very  finely  ground  and  prepared, 
they  are  mixed  with  a  flux  or  other  vehicle  and  ap- 
plied in  various  ways  under  or  over  the  glaze.  Sim- 
ple colours  can  be  made  from  the  metallic  oxides. 
They  should  be  finely  ground  in  a  mortar  well  mixed 
with  a  little  of  the  glaze  with  which  they  are  to  be  used. 
This  will  do  for  the  simplest  work.  For  more  subtle 
colours  rather  involved  processes  are  necessary. 
The  range  of  manufactured  colours,  both  over-  and 
under-glaze,  is  wide  enough  to  suit  all  tastes,  and  when 
working  on  a  small  scale  are  infinitely  to  be  preferred 
on  the  score  of  economy  and  dependability. 

A  method  of  painting  entirely  suited  to  beginners 
is  as  follows :  A  simple  palette  is  prepared  with  the 
colours  ground  upon  a  slab  of  glass.  The  medium 
employed  is  a  solution  of  gum  arabic  and  water, 
the  colours  being  applied  directly  to  the  green  shape 
with  a  brush.  The  difficulty  of  firing  glaze  on  the 


135 

raw  clay  deters  any  attempt  at  high  finish,  and  the 
absorbent  ground  develops  a  desirable  freedom  and 
directness  of  touch.  When  painted,  the  pot  is  dipped 
or  poured  in  a  transparent  glaze  and  fired.  The  gum 
prevents  the  colour  shifting  during  the  immersion,  but 
does  not  prevent  the  glaze  adhering.  This  method  can 
be  satisfactorily  employed  on  biscuit.  More  finish 
can  be  obtained  and  a  richer  glaze  used  without 
risk.  Much  skill  and  practice  will  be  required  to 
produce  good  stuff,  as  each  touch,  although  not 
apparent  before,  will  stand  out  distinctly  and  often 
disagreeably  after  the  fire.  The  gum  must  be  used 
sparingly ;  any  excess  will  cause  peeling  and  prevent 
the  adhesion  of  the  glaze. 

For  a  still  higher  finish  the  biscuit  is  sized  with 
a  solution  of  gum  tragacanth.  This  is  smoothly 
applied  until  the  pot  is  non-absorbent.  The  design, 
if  elaborate,  should  be  drawn  upon  the  pot  with  a 
fine  graphite  pencil  or,  better  still,  India  ink  and 
brush.  A  common  pencil  is  likely  to  show  after 
firing,  but  the  ink  disappears  entirely.  The  colours 
are  then  well  ground  and  laid  in  with  fat  oil  of 
turpentine  or  lavender  oil. 

To  prepare  the  first  oil,  half  fill  a  cup  with  pure 
turps,  stand  it  in  a  saucer,  and  spill  a  little  over  the 
sides  of  the  cup.  After  standing  a  little  the  fat  oil 
is  deposited  in  the  saucer  and  the  clear  turps  left  in 
the  cup.  Long,  flexible  brushes  holding  plenty  of 


136 

colour  are  used  and  the  fat  oil  thinned  if  necessary 
with  clear  turps.  The  colour  should  flow  easily 
from  the  brush,  being  neither  tacky  nor  too  fluid,  and 
constant  retouching  is  to  be  avoided.  Keep  all  free 
from  dust.  Heavy,  greasy-looking  masses  should  be 
scraped  off  and  repainted,  otherwise  they  will  flake 
off. 

When  the  painting  is  finished,  the  colour  is  hardened 
on  ;  that  is,  the  gum  and  medium  are  fired  off  in  the 
kiln,  a  dull  red  heat  being  sufficient.  This  does  any- 
thing but  harden  on,  however,  and  the  pot  must  be 
handled  very  carefully  or  the  colour  will  rub  off.  The 
glaze  should  now  be  gently  sprayed  on,  and  then  the 
final  fire  is  given. 

Another  way  is  to  apply  a  very  thin  spray  of  glaze 
before  hardening  on,  just  sufficient  to  fix  the  colour. 
The  pot  may  then  be  dipped  or  poured  without  risk. 
In  each  case  the  oily  medium  must  be  quite  dry 
before  the  hardening  on  takes  place.  After  the  glost 
fire  the  decoration  is  fixed  and  unalterable.  Where 
possible,  a  hard  transparent  glaze  is  best  for  fine 
work.  A  soft  glaze  will  always  run  if  slightly 
over-fired,  and  the  result  is  the  obliteration  of  all 
brushwork. 

Over-glaze  decoration  is  applied  in  a  very  similar 
manner.  Turpentine,  fat  oil,  and  lavender  oil  are 
used :  the  turps  to  run  the  colour,  the  fat  oil  to 
stiffen,  and  the  oil  of  lavender  to  retard  the  drying. 


137 

The  colour  must  be  applied  evenly  and  thinly,  thick 
patches  being  likely  to  peel  or  crack.  On  hard 
glazes  this  process  lends  itself  to  elaborate  effects. 
The  hard  and  fast  colours,  the  blues  and  greens, 
may  be  fired  first,  the  delicate  pinks  and  greys  last. 
The  whole  effect  may  then  be  enriched  with  low- 
firing  lustres.  These,  when  bought  in  bottles,  are 
ready  to  use  and  are  applied  directly  with  a  fine 
brush,  then  fired  at  a  dull-red  heat.  The  pot  should 
then  be  quite  finished ;  quite  frequently  it  is. 

Pate  sur  pate  or  painting  in  relief  colours  is  another 
process  that  has  many  attractive  features.  The 
colours  have  a  clay  carrier  and  are  applied  with  a 
gum  medium.  Painted  boldly  with  a  certain  amount 
of  relief,  this  gives  a  rich  enamel  effect  very  suitable  to 
simple  figure  decoration. 

The  full  equipment  of  the  painter  will  be  as  follows : 

Colours,  under-  or  over-glaze. 

Brushes,  tracers,  and  shaders. 

A  stick  frame  for  holding  the  vase. 

Turpentine  and  lavender  oil. 

A  slab  of  ground  glass. 

A  muller  for  grinding. 

India  ink  and  a  colour  slab. 

A  palette  knife  of  horn  for  very  delicate  col- 
ours. 

Some  soft  rags. 
Before  risking  decent  shapes  in  the  fire,  trials,  —  on 


138 

biscuit  for  under-glaze,  on  glaze  for  over-glaze, — 
should  be  made  repeatedly.  Graduated  strips  and 
stripes  tartan  fashion  are  the  most  useful  and  easily 
tabulated.  To  lay  perfectly  flat  grounds  some  skill  and 
practice  are  necessary.  One  method  is  to  paint  in 
the  ornament  or  rather  the  space  it  will  cover  with 
thick  molasses  or  black  treacle.  This  is  allowed  to 
harden  and  the  background  colour  applied  with  a 
soft  dabber.  It  must  be  ground  fine  with  fat  oil  and 
applied  very  evenly.  Then  the  tile  or  vase  is  soaked 
in  water,  which  causes  the  treacle  to  peel  off.  The 
oil  is  allowed  to  dry  and  the  piece  fired.  This 
fixes  the  background,  and  the  decoration  itself  is 
next  applied. 

Pierced  work  if  skilfully  done  is  most  attractive. 
The  pattern  may  be  incised  on  the  "original,"  which 
is  moulded,  the  design  then  showing  in  relief.  This 
again  shows  as  a  slightly  engraved  pattern  on  each 
cast  form  or  shape.  Then  with  the  aid  of  a  fine- 
pointed  knife  or  plaster  tool  the  pattern  is  cut  out 
and  the  edges  are  softened  to  take  away  any  metallic 
look.  The  Chinese  and  Persians  are  said  to  have 
used  rice  seeds  in  some  of  their  translucent  effects. 
The  seeds  were  embedded  in  the  moist  clay  to  form 
a  delicate  tracery.  When  fired,  the  grains  disap- 
peared, leaving  holes  which  were  completely  filled 
with  glaze. 

The  decorative  possibilities  of  simple  incised  lines 


139 

and  plain  slip  additions  have  been  hinted  at  already. 
The  slip  may  be  coloured  red  or  brown  with  iron  and 
manganese  oxides  or  applied  white  to  a  coloured 
body.  Sharply  incised  lines  may  be  filled  in  with 
colour  stiffened  by  the  addition  of  a  little  hard  clear 
glaze  or  China  clay.  Patterns  may  be  dug  out  or 
stamped  in  and  filled  up  with  different  coloured 
clays  and  the  whole  glazed  with  a  coloured  transpar- 
ent glaze.  Scraffito  work  is  effective  and  not  diffi- 
cult. The  green  pot,  tile,  or  dish  is  sprayed  evenly 
with  a  different  coloured  slip,  usually  red  on  white. 
The  piece  should  not  be  quite  dry  and  the  coeffi- 
cient of  expansion  between  the  two  clays  as  near 
alike  as  possible.  The  decoration  is  then  sketched 
in  and  the  background  or  the  ornament  itself  gently 
scratched  away  to  show  the  ground  beneath.  It  is 
then  fired,  glazed,  and  fired  again.  All  these  pro- 
cesses have  their  uses  and  abuses,  but  they  do  not 
lend  themselves  readily  to  elaboration  or  realism. 


SIATO 
fORA1 

P1EC 


FIG.  56 


CHAPTER  XIV 

FIGURINES 

"But  if  you  carve  in  the  marble  what  will  break  with  a 
touch,  or  mould  in  the  metal  what  a  stain  of  rust  or 
verdigris  will  spoil,  it  is  your  fault  not  mine." 

—  RUSKIN. 

THE  making  of  small  figures  is  an  important  de- 
partment of  ceramics]  scarcely  mentioned  so  far. 
It  is  one  offering  exceptional  opportunities  to  the 
advanced  craftsman.  In  this  branch  of  potting, 
even  more  than  any  other,  the  possibilities  and  limi- 
tations of  the  clay  and  glaze  need  close  study  if 
best  results  are  to  be  obtained.  The  archaic  Sung 
and  Tang  figures  and  the  well-known  Tanagras  are 
far  better  guides  to  the  beginner  than  the  wonderful 
Dresden  porcelain  or  the  bisque  groups  of  Sevres. 
The  Chinese  and  Japanese  in  their  glazed  figures 
show  remarkable  appreciation  and  utilization  of  the 
plastic  and  liquid  qualities  of  their  medium.  Splen- 
did and  sound  work,  too,  has  been  turned  out  in 
recent  years  in  Germany  and  Austria,  whilst  the 
Copenhagen  porcelain  is  world  famous. 

To  start  with,  the  simplest  decorative  figures 
might  be  attempted.  Many  of  the  little  deities  of 

141 


142 


FIG.  57 


ancient  Egypt  offer  rich 
suggestions  for  two-  or 
three-piece  moulds.  Jap- 
anese Netsuke  and  Scan- 
dinavian bone  carvings 
are  other  stimulating,  if 
more  remote,  fields. 
Next,  a  more  ambitious 
but  still  uncomplicated 
figure  could  be  moulded 
directly  from  the  clay. 
As  the  difficulties  of 
moulding  increase,  the 
original  clay  may  be  first 
fired  or  a  good  plaster 
cast  made.  In  firing  the 
figure  a  very  slow  fire 
must  be  used,  and  the 
modelling  must  be  done 
carefully,  as  free  from 
holes  as  may  be,  and 
without  an  armature. 
Air  holes  are  apt  to  blow, 
and  additions  of  soft  clay 
to  the  model  when  hard  are 
likely  to  crack  off  in  firing. 
With  a  plaster  original 
some  retouching  is  pos- 


143 

sible  before  the  final  piece-mould  is  made.  When 
modelling  the  head  and  face,  the  modifying  effects  of 
the  glaze  used  must  be  realized,  so  that  such  detail  as 
may  be  depicted  shall  have  its  full  value  in  the  finished 
figure.  Too  much  realism  in  draperies  with  conse- 
quent under-cutting  is  to  be  avoided,  and  the  inclina- 
tion of  all  but  the  high-temperature  glazes  to  leave 
prominent  parts  and  pool  in  hollows  must  be 
heeded.  Sharp  edges  are  always  bad,  and  projections 
that  are  liable  to  crack  in  the  fire  or  break  at  a 
touch  are  a  fruitful  source  of  loss,  and  are,  at  the 
best,  doubtful  craft.  It  is  quite  possible  to  produce 
delightful  figures  glazed  with  low-firing  glazes,  and 
where  a  wide  range  of  colour  is  desired,  they  are  the 
only  glazes  available.  But  for  delicate  modelling, 
where  colour  is  a  secondary  consideration  and 
where  refinements  may  be  obscured  by  too  much 
gloss,  the  grand  feu  porcelain  or  salt  glaze  are  the 
best  and  only  alternatives. 

But  each  man  to  his  taste.  We  will  start  with  a 
simple  two-piece  mould  for  pressing.  Small  objects, 
not  necessarily  figures,  may  be  modelled  in  the 
round,  being  designed  therefore  without  under-cut  to 
pull  in  two  halves.  They  should  be  highly  finished 
and  then  biscuited.  The  fired  original  is  then 
shellacked  or  oiled  and  carefully  bedded  in  clay  up  to 
the  halfway  line.  If  the  figure  be  first  dusted  with 
French  chalk,  it  will  leave  the  clay  without  trouble. 


144 


KGDVi 


Little  walls  being  built,  the  first  half  is  then  cast. 
When  set,  the  biscuit  figure  is  removed,  the  sides  of 
the  mould  trimmed,  the  joggles  cut,  and  the  figure 
fitted  back.  The  sides  are  carefully  clay  washed  or 

oiled  and  the  second 
half  of  mould  cast. 
When  set,  the  two 
halves  are  gently 
pried  apart  and  a 
groove  hollowed  out 
all  round  the  inner 
edge  of  the  mould. 
(Figs.  58  and  59.) 
This  groove  is  for 
the  reception  of  any 
surplus  clay  that 
would  otherwise 
squeeze  between  the 
two  parts  of  the 
mould  and  prevent 
their  perfect  adjust- 
ment. To  make  a 
press,  each  half  of  the  mould  is  carefully  filled  with 
clay,  well  pressed  in.  Then  they  are  applied  and 
firmly  squeezed  together,  until  the  two  halves  fit  ex- 
actly. The  press  is  then  removed  and  trimmed  up. 
The  second  essay  might  follow  the  lines  of  the 
statuette  here  illustrated  for  the  three-piece  mould. 


FIG.  58 


145 


FIG.  59 


A  decorative  treatment,  giving  stiff  lines  and  a 
simple  silhouette,  is  chosen.  The  hands  are  concealed, 
and  the  face,  the  only  flesh  showing,  clearly  cut  out 
by  the  costume.  The  sec- 
tion shows  the  compara- 
tive depth  of  the  folds 
in  the  drapery.  Three 
pieces  only  were  used  for 
the  mould,  indicated  by 
the  illustration.  (Fig.  63.) 

In  moulding  from 
plaster  or  biscuit  the 
model  must  be  absolutely 
non-absorbent  and  should 
be  carefully  treated  with  shellac,  beeswax  dissolved  in 
turpentine,  or  parting.  Beeswax  is  best  for  fine 
work  and  should  be  applied  very  thinly  and  re- 
peatedly. Clay  originals  need  no  preliminary  treat- 
ment, if  the  clay  is  still  plastic. 

The  divisions  of  the  mould  being  decided  upon, 
plastic  clay  is  rolled  out  thin,  cut  into  strips,  and 
built  round  the  section,  as  shown  in  the  illustrations. 
(Figs.  60  and  61 .)  The  exposed  figure  within  the  clay 
walls  is  then  very  slightly  filmed  with  olive  oil. 
The  plaster  is  then  mixed  and  thrown  on  or  poured. 
The  walls  should  stand  out  at  right  angles  to  the 
circumference  of  the  figure  or  so  nearly  as  the  exi- 
gencies of  the  figure  permit.  They  should  be 


146 


FIG. 


CLAY       \uttresscd 
S      w"ere    needing 
support,  and  be 

FKONT     deeP  enough  to 
give  a  good 
thickness  to  the 
mould.      When 
the  plaster  sets, 
they  may  be  re- 
moved,   and 
when    quite 
hard,  the  plaster 
itself  detached. 
This    comes 
away    quite 
readily  from  the 
clay,  but  is  apt 
to     hold     on 
plaster  or   bis- 
cuit.     A   little 
water    dropped 
from     a    clean 
sponge  onto  the 
cleaving    line 
will    often    re- 
lease   the    two 
parts. 

The  model  is 


cleaned  up  and  the 
sides  of  the  first  sec- 
tion trimmed,  slight 
joggles  made  where 
they  will  not  bind, 
and  the  edges  care- 
fully shellacked  or 
clay  washed.  (Fig.  62.) 
Model  and  section  are 
then  fitted  together 
and  the  next  section 
made  in  a  similar 
manner,  except  that 
only  one  wall  of  clay 
will  be  built.  The 
second  section  is 
treated  in  the  same 
way,  and  for  the  last 
piece  the  clay  wall  is 
unnecessary,  the 
plaster  being  poured 
directly  in  between 
the  two  other  sec- 
tions. Where  the 
plaster  has  to  be 
sprinkled  on,  or  there 
is  any  danger  from 
splashes,  the  exposed 


FIG.  61 


F1R/T 
JflECfOf-  MOULD 

Fio.  62 


parts  of  the  model 
should  be  protected 
with  soft  paper. 

The  last  piece  be- 
ing set,  the  original 
is  removed,  the 
mould    assembled, 
trimmed,  or  fettled, 
tied  up,  and  set  to 
dry.     The  casting, 
or  pressing  if  it  be 
large  enough,  is  pro- 
ceeded with  as  Jbe- 
fore  described,  the 
slip   being   poured 
in   at    the  base. 
When     removed 
from    the    mould, 
the  open   base   of 
the   cast   may    be 
closed  with  a  thin 
slab    of    clay   slip 
poured    on     to    a 
plaster  bat  and 
allowed  to  set  for 
that  purpose.  When 
tough,    the    figure 
should  be  touched 


149 


SECTION  OF  ABECEMoqU) 

&KFJAINING 
CATEWTH 
FLATTOP  TO 
FACILITATE 
TBJO/ING  - 


FIG.  63 

up  with  skill  and  reticence.  Finally,  a  little  hole  is 
made  in  the  closed  base  and  another  as  inconspicu- 
ously as  may  be  in  the  back  of  the  head,  to  prevent 
blowing  in  the  fire. 

With  more  complex  figures  many  more  pieces  will 
be  needed  for  the  mould.  They  are  made  in  the  same 
way,  but  are  carefully  trimmed  and  then  encased  in 
an  outer  frame  or  jacket  of  plaster.  (Fig.  63.)  Large 
figures  should  be  pressed ;  the  head  first,  the  different 


150 


sections  of  the  mould  being  fitted  into  the  containing 
case  as  the  work  progresses.  More  retouching  is 
needed  with  pressed  figures,  but  the  time  spent  is 
well  spent,  for  they  possess  a  substance,  and  when 
retouched  with  art,  a  character,  that  is  lacking  in 
the  more  fragile  cast. 


IMPART  OF: 

MoqL; 


WcClTON  /HEWING 
DttTHOFFOLIV  INPRAEEKY 

FIG.  64 


£arly 


FIG.  65 


CHAPTER  XV 

KILNS 

"By  many  long,  laborious,  and  chargeable  experiments 
he  hath  found  out." 

—  Extract  from  an  old  potter's  patent. 

WHAT  must  be  the  first  representation  of  a  kill, 
or  kiln,  is  found  at  Beni  Hassan.  It  appears  to  be 
square  in  form,  and  the  potter  is  shown  feeding  the 
fire  at  the  base.  In  the  same  illustration  he  is 
depicted  unpacking  or  drawing  the  ware  from  the 
top.  The  cut  from  the  Greek  Hydra  gives  a  very 

151 


152 

similar  kiln,  but  a  vessel  in  the  museum  of  Berlin 
shows  one  with  a  beehive  shape. 

The  kilns  left  scattered  about  Europe  by  the 
Romans  were  usually  of  this  domed  kind,  circular 
in  plan,  with  one  fire  hole.  The  floor  of  the  kiln 
was  of  pierced  slabs,  and  the  flames  issuing  thence 
enveloped  the  ware  piled  within  and  escaped  through 
a  vent  in  the  top.  The  packing  and  firing  is  de- 
scribed in  Ceramic  Art  in  Great  Britain,  by  L. 
Jewitt,  F.S.A.  It  fully  explains  the  trepidation  of 
the  old  potters,  who,  before  each  firing,  were  wont 
to  consult  the  moon  and  stars  and  evoke  the  aid  of 
the  gods.  This  is  happily  set  forth  in  Cowper's 
translation  of  one  of  Homer's  epigrams,  wherein  he 
expresses  the  pious  hope  that  if  the  false  potter 
"stoops  to  peep  into  his  furnace,  may  the  fire  flash 
in  his  face  and  scorch  it";  a  risk  often  faced  by 
potters,  false  or  true! 

The  smothering,  or  reducing,  as  then  practised,  was 
similar  to  the  lustring  methods  used  in  Italy  in 
the  sixteenth  century,  or  in  the  manufacture  of  the 
blue  bricks  to-day.  The  Japanese  and  Chinese 
built  small  kilns  in  tiers  on  the  side  of  a  hill.  Start- 
ing with  the  lowest,  the  waste  heat  was  utilized  to 
warm  up  the  kiln  above,  thus  saving  time  and  fuel. 
The  Chinese  used  heavy  saggars,  and  specimens  of 
these  with  portions  of  melted  pots  still  adhering  to 
them  attest  the  enormous  heats  to  which  they 
frequently  attained. 


153 

Modern  kilns  subdivide  roughly  into  biscuit, 
glost,  and  enamel.  The  first  is  used  for  firing  the 
green  or  clay  shapes,  the  second  for  the  hard  fire  of 
the  glazed  ware,  and  the  last-named  for  fixing  on  the 
added  decoration.  Sometimes  a  kiln  is  used  for  the 
double  function  of  biscuiting  and  glazing. 

Of  modern  kilns  the  one  still  most  widely  used 
approximates  to  the  bottle-shaped,  simple,  up-draught 
kiln.  It  contains  one  or  two  chambers  with  hatch 
for  entry,  flue  or  chimney,  and  anything  from  three 
to  nine  fire  holes.  The  section  of  such  a  kiln  is  here 
shown  and  represents  a  fair  average  up-draught  kiln 
(Fig.  66),  variants  of  which  type  are  working  in  most 
pottery  districts  to-day.  In  these  kilns  the  flames 
rush  in  at  the  fire  holes,  play  on  the  built-up  bungs  of 
saggars,  and  escape  through  the  top  vent.  In  a  two 
chamber  kiln,  as  sometimes  used  for  porcelain,  the 
glaze  is  put  in  the  lower  chamber  to  receive  the 
hottest  fire,  the  biscuit  in  the  upper  getting  a  gentle 
fire.  Where  the  fire  enters  directly  into  the  kiln  in 
any  large  volume,  bags  or  small  chimneys  are  built 
up  inside  the  mouths  to  save  the  saggars  from  the 
worst  of  the  fire.  Of  late  the  single-chamber,  down- 
draught  kiln  has  come  into  favour,  as  it  is  easily 
packed  and  economical  of  heat.  Bags  of  firebrick 
protect  the  saggars  from  the  roughest  fire  and  direct 
the  flames  to  the  crown  of  the  chamber,  from  which 
point  they  descend  to  pass  out  through  flues  in  the 


155 


POWNDRAIJGHT  KILN 

55? 


FIG.  67 


floor  of  the  kiln.  (Fig.  67.)  Biscuit  ovens  are  often 
of  this  type,  either  domed  or  flat  arched. 

The  most  recent  innovations  are  gas  and  oil  kilns. 
They  require  comparatively  little  manual  labour 
in  the  firing,  are  easily  regulated,  and  the  waste  heat 
is  frequently  used  for  secondary  purposes.  Their 
freedom  from  smoke  and  their  economy  of  labour 
and  money  must  eventually  render  the  other  types 
obsolete. 

These  large  kilns  are  strongly  banded  with  iron 
supports  designed  to  prevent  too  much  loosening 
of  the  walls  when  expanded  by  the  great  heat.  A 
very  important  point  is  the  draining  of  their  site, 


156 


FIG.  68 

as  large  kilns  tend  to  attract  moisture,  and  the 
presence  of  steam  in  a  kiln  is  productive  of  much 
damage. 

Enamel  kilns  are  used  for  the  final  processes  where 
the  glazed  pot  is  painted  with  over-glaze  or  enamel 
colours.  They  are  of  no  great  size  and  are  made  of 
fire-clay  slabs  or  even  iron  plates  when  the  enamel  is 
soft.  The  flames  play  all  round  the  muffle  or  fire- 
clay box  during  the  firing,  but  no  flame  or  fume  is 
allowed  access  to  the  inside.  (Fig.  68.) 


157 

In  packing  a  kiln  with  biscuit  or  glaze  much  care, 
thought,  and  expedition  have  to  be  exercised.  An 
experienced  setter  is  essential  in  a  factory  if  the  pots 
are  to  have  every  chance  in  the  fire,  for  all  kilns  vary 
and  have  their  hot  and  cool  corners.  First,  the  floor 
is  well  bedded  with  quartz  sand  or  flint  that  will  not 
vitrify  but  will  provide  a  good  setting  for  the  bottom 
saggars.  These  saggars  are  fireclay  boxes,  round  or 
oval,  rarely  square,  and  without  lids,  in  which  the 
pots  are  placed.  Piled  one  above  another  they  form 
the  bungs,  the  bottom  of  one  supplying  the  top  of 
that  beneath.  These  bungs  are  built  at  intervals 
that  permit  the  flames  to  penetrate  between  them  and 
give  a  good  even  fire  all  over  the  chamber. 

In  actual  practice  some  parts  of  a  kiln  are  hotter 
than  others,  and  it  is  here  that  a  good  setter  shows 
his  capabilities,  setting  the  thin  wares  in  the  softest 
places  and  putting  the  heavier  biscuit  or  hard  glaze 
in  the  hottest  corners.  With  biscuit  the  setting  is 
not  difficult  except  where  delicate  or  friable  ware 
may  need  very  careful  bedding  and  propping. 
With  clean  saggars  the  biscuit  may  touch  the  sides, 
and  a  competent  man  will  pile  an  enormous  amount 
of  biscuit  into  a  kiln  without  risk.  In  the  glost  kiln 
the  ware  requires  gentle  handling  and  must  touch 
nothing  but  the  spur  or  support.  The  saggars  are 
usually  given  a  saggar  wash  of  lead  and  stone  to 
prevent  them  absorbing  glaze  from  the  wares,  for 


158 

a  glazed  pot  placed  too  near  a  raw  saggar  is  very 
likely  to  come  out  with  a  thin  or  dry  patch. 

When  the  pot  is  firmly  placed  on  its  stilt,  a  roll  of 
pugging  is  placed  round  the  rim  of  the  saggar ;  this 
provides  a  firm  bed  for  the  next  above  it  and  also 
stops  the  entry  of  dust  and  flame.  This  pugging 
is  made  from  clay  or  marl  mixed  with  ground  sherds, 
sieved  gravel,  or  some  non-vitreous  dust  to  prevent 
it  sticking  to  the  saggars.  The  plugging  is  made 
malleable  with  a  little  water  and  rolled  out  by  hand 
or  pressed  through  a  die.  It  will  readily  be  seen 
that  a  carelessly  built  bung  of  any  height  may  slip 
in  the  stress  of  firing,  and  its  fall  would  most  likely 
involve  others,  whilst  any  slight  movement  may  be 
sufficient  to  cause  a  vase  to  topple  off  its  stilt.  In 
a  down-draught  kiln  the  bungs  over  any  vent  must 
be  raised  on  fire  tiles  to  permit  the  escape  of  the 
flames.  When  all  the  bungs  are  filled  up  and  piled 
in  position,  the  trials  and  cones  placed,  the  hatch  is 
bricked  up.  Spy  holes  are  left  where  necessary,  and 
the  whole  well  clammed  to  prevent  the  loss  of  heat 
during  firing.  When  fired,  the  hatch  may  be  very 
gradually  loosened  to  accelerate  the  cooling. 

The  fireman's  job  is  one  of  the  most  arduous  and 
important  of  all  the  prolonged  processes  of  potting. 
Coming  as  it  does  at  the  end,  it  may  make  or  mar 
kilns  of  great  value,  and  it  requires  more  than  ordi- 
nary judgement  and  nerve.  The  chief  troubles  arise 


159 


POWN-DRAQGHT  KILN 


rOOTINCJ. 
1-  HEARTH  • 


SECTION  ON 


J.RON  BEAKED 
4.  5TOPHK: 
J.HKEHOLE- 


7.  HATCH- 


ir  »•  o       r      r        -  '  j> 


HALf-PlAN 


FIQ.  69 


160 

from  bad  or  irregular  draught  or  impure  fuel.  They 
express  themselves  in  the  form  of  clinkered  holes, 
excessive  smoke,  and  irregularly  fired  or  sulphured 
ware.  The  term  sulphured  is  applied  to  pots  that 
come  out  gloomy  or  dulled  and  is  said  to  be  equally 
due  to  a  reducing  fire  or  an  oxidizing  one.  In  the 
former  an  insufficiency  of  air  causes  excess  of  carbon 
in  the  kiln  and  the  absorption  of  oxygen  from  the 
glaze.  In  the  latter  an  excess  of  air  (oxygen)  allows 
sulphur  vapour,  if  present,  to  attach  itself  to  the  glaze. 

The  fire  bars,  fire  holes,  and  flues  must  be  kept 
clear  and  the  fuel  carefully  selected  if  these  things 
are  to  be  avoided.  The  aim,  as  previously  stated, 
is  a  gradually  increasing  fire,  sharper  towards  the 
finish.  For  this  purpose  some  potters  finish  off  with 
wood  which  gives  a  long  flame  free  from  sulphur 
and  clears  the  glaze.  Even  when  sulphured,  a  clear 
flame  at  the  finish  will  remove  many  ill  effects. 
The  baiting  should  be  fairly  heavy  at  the  start, 
lighter  and  more  frequent  towards  the  finish,  when 
smoke  in  any  quantity  should  be  avoided. 

For  temperature  gauges,  the  cones  previously  de- 
scribed are  used  and  should  be  placed  in  an  average 
place,  screened  as  much  as  possible  from  draught  or 
flame.  Small  sight  pots  and  glaze  rings  placed  near 
the  spies  can  be  hooked  out  and  examined  and  are 
valuable  aids,  but  their  exposed  position  and  the 
corrosive  action  of  the  flames  must  be  taken  into 


161 


account.  Pyrometers  are  also  used,  but  with  all 
these  aids  the  experienced  fireman  pays  due  regard 
to  sight  and  colour. 

For  a  craftsman,  the  kilns  that  have  been  de- 
scribed are  unsuitable  on  account  of  their  size,  if 
they  are  not  altogether  beyond  his  means.  But  a 
kiln  of  some  sort  is  indispensable  to  a  potter.  The 
craftsman  is  nothing  if  not  inventive.  Small  trials 
can  be  fired  in  crucibles  in  an  open  fire  or  on  a  gas 
ring.  I  have  heard  of  some  preliminary  success  with 
a  gas  cooker,  discounted  later  by  a  frontal  attack 
from  the  cook.  Considerable  knowledge  can  be 
gained  from  small,  easily  constructed,  experimental 
kilns. 

The  small  trial  kiln  shown  (Fig.  70)  was  constructed 
with  a  stout  old  crock, 
over  which  was  built  a 
core  of  bricks  plastered 
with  marl.  The  fire  was 
started  at  each  corner  at 
the  bottom,  and  when  well 
alight,  fed  from  the  top 
with  coke.  A  small  spy 
at  one  corner  closed  with 
a  piece  of  biscuit  gave 
some  idea  of  the  progress  of  the  firing.  This,  of 
course,  had  to  be  practically  rebuilt  at  each  firing, 
but  as  a  makeshift  was  quite  satisfactory. 


CKDCKSHTH 
JPV-HOU  .  CONL IN/IPE 


FIG.  70 


162 


CROCK  M1CKFD  CMfc 
VLA/TERLD  WITH  MAKL 


The  gas  and  oil  kilns  described  in  Chapter  IX  are 
excellent  as  far  as  they  go,  and  indeed  the  only 
practicable  kind  for  indoor  schools.  But  their 

restricted  size  soon  be- 
comes irksome  to  a  crafts- 
man, whilst  the  expense 
of  firing  makes  only  the 
finest  work  remunera- 
tive. For  over-glaze 
work  they  are  excellent, 
but  for  some  reason 
glazes  fired  in  them  seem 
to  lack  some  of  the  rich- 
ness and  maturity  the 
same  glazes  exhibit  when 
fired  in  the  slower  and  more  soaking  fire  of  a  brick 
kiln.  The  dug-out  kiln  here  depicted  (Fig.  71)  would 
be  quite  suitable  for  summer  schools  or  for  a  crafts- 
man making  soft  peasant  pottery.  The  section  and 
sketch  will  indicate  its  construction.  The  materials 
are  hard  bricks  and  stout  old  boiler  plates,  or  sheet 
iron.  To  pack  or  unpack,  the  middle  section  of  the 
roof  would  have  to  be  removed  each  time,  and  all 
glazed  pots  would  need  protection  from  scalings  and 
gravel  from  above.  The  roof  will  sag  at  any  big  heat, 
and  if  of  thin  iron,  will  need  propping.  The  firing 
would  be  done  with  soft  coal  or  wood ;  a  very  slow  start, 
with  a  brisk  draught  and  a  long  flame  at  the  finish. 


FIG.  70s 


163 


IRON  ROOF. 


INDUCL 
DRAUGHT 


'DUGOVT* 
KILN- op 

COMMON 
REDBRICK. 


BRICK/ TO 
KKLABOS/t  fUOOR,. 


FIG.  71 

Of  course  the  front  will  be  hotter  than  the  back, 
but  if  saggars  can  be  obtained,  the  glaze  may  be 
placed  in  them  to  the  front  with  the  biscuit  protected 
behind.  Clay  shapes  fired  up  at  the  front  may  bend 
towards  the  fire,  and  any  broken  crocks  should  be 
used  to  screen  them. 

The  making  of  rough  saggars  is  not  difficult  if  a 
supply  of  fireclay  is  to  hand,  or  clay  and  grog  will 
serve  at  a  pinch.  The  clay  is  rolled  out  and  the 
saggar  stuck  up,  much  as  described  on  page  32. 


164 


EAKTH 
WLLWMMU 

SECTION  OF  DUG-OUTKILN 


FIG.  71* 

Every  joint  must  be  carefully  welded  and  the  whole 
thoroughly  dried.  Then  they  are  fired  up  in  the  kiln, 
very  gently  at  first,  and  carried  up  to  a  temperature 
considerably  above  that  which  they  will  be  subjected 
to  when  in  use. 

For  small  trial  crucibles  ordinary  clay  mixed  with 
pitchers  and  powdered  coke  proves  satisfactory; 
the  coke  when  fired  out  renders  the  body  porous  and 
the  heat  penetrates  more  swiftly. 

To  construct  the  muffle  kiln  shown  at  Fig.  72  the 
aid  of  a  competent  bricklayer  would  probably  be 
required.  In  this  kiln  glaze  and  biscuit  would  fire 
up  without  saggars,  but  will  take  rather  longer. 
The  plan  and  elevation  of  this  particular  kiln  are 
given  with  all  reserve.  The  design  would  probably 


165 


FIQ.  72 


require  considerable  adjustment  and  modification 
before  complete  satisfaction  was  obtained. 

A  down-draught  kiln,  although  more  difficult  to 
construct  than  an  up-draught,  is  more  economical 
in  the  end  and  does  its  work  more  evenly.  For  the 
Benefit  of  those  that  may  like  to  build  a  small  and 
moderately  cheap  kiln  drawings  are  here  given.  This 
Jdln  was  built  by  me  when  I  had  very  little  practical 
experience  of  kilns  other  than  gas,  but  it  served  its 
purpose  well.  It  was  not  banded,  but  this  is  essen- 
tial if  the  kiln  is  to  stand  hard  and  frequent  fire. 
Firebricks  were  used  for  the  fireholes,  flues,  floor, 
core,  and  dome;  strong  stock  bricks  for  the  rest. 
The  glazed  ware,  which  was  fired  harder  than  the 
biscuit,  was  saggared  in  bungs  as  usual  up  to  about 
five  feet;  the  biscuit  piled  on  top  and  protected 
by  old  saggars  and  cracked  pots  from  the  roughest 


166 


/HLW1NC 
ARKANGE. 
-MENTOF 


Fio.  72a 

fire.  There  were  no  bags  in  this  kiln,  but  the  saggars 
used  were  very  strong  and  had  stood  a  much  greater 
heat  than  that  to  which  they  were  subjected  in  this 
kiln,  so  that  they  showed  very  little  wear  or  tear 
after  twenty  firings.  The  stack  of  sixteen  feet  gave 
a  good  sharp  draught,  increased  if  necessary  by  the 
addition  of  an  iron  chimney  and  regulated  by  an  iron 
damper.  A  wind  screen  or  hotel  is  advisable  for 
rough  nights,  and  some  sort  of  roof  is  necessary  to 
protect  the  crown  from  the  weather.  It  is  impor- 
tant to  have  the  arch  of  the  hatch  very  strongly  built, 
as  it  has  to  stand  a  lot  of  strain,  and  an  iron  support 


167 


MQFFLE  KILN  KJILT  <f 
FIRE  TlU,/>  EIRE  MICK/ 
AND  CQ5M&ON  RED/- 


HATCH  HICKLD  Up. 
TWO  j?   HOLL/. 


Fia.  72b 


too  near  the  fire  soon  corrodes  and  needs  replacing. 
Another  essential  is  that  the  site  be  as  dry  as  possi- 
ble and  the  foundation  made  solid  with  concrete; 
otherwise  even  a  small  kiln  is  liable  to  settle  and 
crack.  With  a  little  extra  expense  a  kiln  of  this 
kind  could  be  banded  round  the  impost  and  fire- 
holes,  thus  considerably  prolonging  its  life. 


168 


POKER: 
./LICE- 


FIG.  73 


In  firing  this  kiln  about  half  a 
ton  of  coke  and  three  quarters  of 
a  ton  of  good  hard  coal,  giving 
a  long  flame,  was  used.  Coke 
for  the  slow  fire  was  first  started 
on  the  bottom  and  maintained 
for  sixteen  or  eighteen  hours, 
lifted  up  on  to  the  bars  for 
another  six  or  eight  hours, 
when  the  saggars  would  begin 
to  show  signs  of  colour.  The 
coal  fire  was  then  started  about 
the  24th  or  25th  hour  and  con- 
tinued another  18  hours,  more 
or  less,  according  to  the  varying 
conditions,  making  in  all  some 
40  or  45  hours.  This  gave  a 
very  evenly  graduated  heat  from 
cone  1  at  the  base  to  cone  .03 
at  the  top.  Bags  were  tried 
experimentally,  but  whilst  giv- 
ing a  more  uniform  heat,  took 
much  longer  to  fire  up.  At  the 
finish  of  the  firing  the  fireholed 
were  bricked  up,  the  damper 
closed  when  the  fires  died  down. 
In  about  24  hours  the  vent  and 
the  hatch  were  eased  a  little  at 


169 


the  top,  and  in  48  hours  it  was  pulled  down  and  the 
drawing  commenced.    Packed  with  the  hard  glazes 


SAGGAR 

POTINSIDL 


FIG.  74 


at  the  bottom  and  the  soft  at  the  top  this  kiln  an- 
swered excellently  for  the  purposes  for  which  it  was 
required. 


CHAPTER  XVI 
THE  EDUCATIONAL  VALUE  OF  POTTERY 

"The  principal  point  in  Education  is  that  one's  knowledge 
of  the  World  begins  at  the  right  End." 

—  SCHOPENHAUER. 

THE  study  of  the  fictile  art  of  the  potter,  even 
from  the  theoretical  side  alone,  cannot  fail  to  quicken 
and  broaden  education.  The  antiquity  of  the  craft, 
stimulating  research  amongst  the  records  of  ancient 
civilizations,  brings  to  light  customs  and  habits 
bearing  very  closely  upon  the  earliest  struggles  of 
man  to  emancipate  himself  from  mere  brute  sur- 
roundings. The  primitive  decorations  rudely 
scratched  on  clay  vessels  antedate  and  forecast  the 
hieroglyphic  and  sign  languages  of  all  nations. 

It  would  be  but  hyperbole  to  claim  that  without 
clay  the  Mosaic  tablets  would  have  remained  un- 
written, but  indubitably  the  clay  cylinders  of  Assyria 
gave  a  strong  impulse  to  the  development  of  cipher- 
ing and  writing  and  the  spread  of  learning,  —  an  im- 
petus not  to  be  derived  from  the  obstinate  granite 
medium  so  generally  employed  by  the  Egyp- 
tians. 

It   is   this   amenable   ductile   quality,   so   easily 

170 


171 

receptive  of  the  most  emotional  touch,  that  has  made 
and  still  makes  clay  such  an  admirable  medium  of 
expression  for  the  young,  —  whether  young  in  the  his- 
tory of  the  world  or  young  in  actual  years.  And 
this  malleability  is  accompanied  by  a  tenacity  that 
permits  slow  building  up,  remodelling,  and  high 
finish,  suitable  to  work  of  the  most  painstaking 
character.  To  this  is  added  the  fixed,  unalterable 
quality  imparted  by  fire,  so  that  pottery  more  than 
any  other  craft  preserves  an  imperishable  record  of 
the  ages. 

This  positive  chronicle  is  valuable  alike  to  the 
savant  or  the  student.  Indeed  the  most  trivial 
child's  toys  of  the  Hellenes,  the  quaint  water  pots  of 
the  Peruvian  peasant,  or  the  unassuming  tea  bowl 
of  the  esoteric  followers  of  Riku  may  chance  to 
convey  to  the  sincere  student  a  clearer  idea  of  the 
habits  and  thoughts  of  their  producers  than  many  a 
pedantic  treatise  or  translation. 

"  So  lively  shines 

In  them  Divine  resemblance  and  such  grace 
The  hand  that  made  them  on  their  shape  hath  poured." 

—  MILTON. 

Coming  down  to  points  in  close  contact  with  the 
curricula  of  schools,  we  all  subscribe  to  the  dic- 
tum of  Ruskin  that  "Everyone,  from  the  King's 
son  downwards,  should  learn  to  do  something  finely 
and  thoroughly  with  his  hands."  What  then  more 


172 

suitable  than  sympathetic  clay  wherein  to  fashion 
the  first  fancies  of  the  child  mind.  It  is  a  medium 
at  once  attractive  and  easy  to  mould,  giving  a  tangi- 
bility and  reality  to  forms  and  things  that  can  never 
be  obtained  by  drawing  or  painting.  Then  the  limit- 
less uses  to  which  clay  is  put,  and,  with  the  develop- 
ment of  hygiene,  increasingly  will  be  put,  have  the 
closest  bearing  upon  the  everyday  life  of  the  child. 
They  are  intimately  connected  with  other  studies 
that  cannot  fail  to  be  rendered  more  attractive  by 
working  in  clay. 

But  clay  work  is  a  branch  now  so  universal  that 
it  seems  unnecessary  to  dwell  upon  its  advantages 
to  the  kindergartener. 

The  valuable  remedial  effects  of  clay  work  upon 
the  defective  are  perhaps  less  widely  known.  The 
manipulation  induces  a  most  beneficial  concentra- 
tion and  provides  a  fine  discipline  without  a  trace 
of  inimical  restraint.  Turning  to  higher  grades,  the 
use  of  clays  should  foster  an  interest  in  the  forma- 
tion, composition,  and  disintegration  of  rocks,  and 
in  the  properties  of  the  products  so  engendered; 
in  short,  a  liking  for  geology. 

With  the  making  of  simple  glazes  and  colours 
will  awaken  an  intelligent  curiosity  concerning  the 
nature  of  minerals  and  metals,  their  actions  and 
reactions  in  the  fire ;  a  lively  sympathy  only  awaiting 
a  touch  to  turn  it  into  a  love  for  chemistry  and 


173 

physics.  Then  as  power  and  ambition  and  crafts- 
manship develop,  there  must  needs  be  a  study  of 
the  history  of  ornament.  This  impinges  too  closely 
upon  history  and  geography  to  fail  to  increase  the 
student's  attraction  towards  these  more  remote  but 
allied  fields. 

Finally,  is  it  not  in  the  realm  of  aesthetics  that 
there  looms  the  ultimate  reward  ?  The  proper 
pursuit  of  pottery  must  eventually  lead  us  "towards 
that  idealization  of  daily  life  .  .  .  and  the  road  that 
connects  the  love  of  the  beautiful  with  the  love  of 
the  good  is  short  and  smooth  "  (President  Eliot). 
In  the  hurried  curricula  of  to-day  art  plays  a  rather 
sorry  part.  Little  time  indeed  is  left  for  contempla- 
tion, for  the  realization  of  all  that  beauty  and  har- 
mony in  our  surroundings  may  mean  to  us  in  our 
everyday  work. 

The  making  of  a  bowl,  with  the  concentration 
required  to  shape  it  in  a  manner  at  once  beautiful 
and  serviceable,  must  quicken  the  perception  of 
beauty  and  sharpen  the  quality  of  judgement,  not 
only  for  things  fictile,  but  in  far  wider  fields.  Thus 
the  things  of  everyday  contact  —  the  tableware,  the 
chairs,  the  doors,  the  windows,  pictures,  ornaments, 
hangings,  and  fittings  —  will  all  come  in  for  intelligent 
scrutiny  and  criticism.  This  in  turn  will  be  carried 
on  and  over  into  matters  civic.  This  must  result 
in  a  careful  estimation,  selection,  and  appreciation 


174 

of  our  surroundings,  bringing  them  into  harmony 
with  our  cultivated  thoughts  and  so  enabling  us  to 
get  through  the  day's  work  with  the  least  amount 
of  useless  friction  and  with  the  greatest  possible 
measure  of  enjoyment,  well-being,  and  well-doing. 


TLAN-OF 
ASMALL 


176 


APPENDIX  I 

THE  EQUIPMENT 

THE  divinity  that  presides  over  potting  is  an  expensive 
as  well  as  an  exacting  mistress.  The  equipment  of  even 
a  small  pottery  is,  unfortunately,  a  matter  of  considerable 
expense.  Try  it  from  whatever  angle  we  may  there  is 
the  cost  of  the  kiln  to  be  faced,  besides  a  host  of  other 
small  but  cumulative  expenses.  The  first  essential  is,  of 
course,  a  roomy  workshop  with  if  possible  a  top  as  well  as 
a  side  light.  If  the  craftsman  means  business,  he  should 
remember  that  the  initial  cost  of  a  kiln  is  often  in  inverse 
ratio  to  its  upkeep.  If  he  would  aspire  to  big  things,  full- 
bellied  pots,  plaques,  reliefs,  and  figures,  — and  every  crafts- 
man would,  —  a  brick  kiln  will  be  wanted.  One  holding 
a  dozen  saggars  could  be  built,  but  where  some  experience 
has  been  obtained  with  materials  and  processes,  a  larger 
one  would  be  more  economical.  With  oil  or  gas  kilns  of 
the  ordinary  school  size  the  cost  of  firing  and  the  extra 
time  is  proportionately  too  great  to  permit  of  any  but 
comparatively  high-priced  pots  being  turned  out.  This 
may  serve  in  some  cases,  but  usually  it  is  not  practical 
potting  where  a  livelihood  has  to  be  obtained.  Where 
only  the  painting  is  to  be  fired  on,  an  oil  or  gas  kiln  is 
exactly  what  is  wanted. 

In  this  appendix  is  given  a  plan  of  a  workshop  that  has  all 
the  equipment  necessary  for  the  whole-hearted  pursuit  of 
the  craft.  In  such  an  one  a  good  craftsman,  capable  of 
N  177 


178 

modelling  and  painting  decently  a  figure  or  a  panel,  a 
good  thrower,  and  a  handy  boy  could  work  wonders. 
They  would  be  capable  of  turning  out  a  surprisingly  wide 
range  of  "  pots  "  :  jugs,  mugs,  pots,  bottles,  bowls,  buttons, 
dishes,  plaques,  panels,  vases,  tiles,  and  statuettes,  —  use- 
ful and  beautiful  things.  Anything  in  fact  worth  doing 
can  be  done  except  fine  tableware  or  those  articles  that 
by  their  nature  demand  more  mechanical  accuracy  than 
is  possible,  or  even  desirable,  for  a  craftsman  to  exhibit. 
Where  much  plaster  turning  for  moujds  was  attempted,  a 
lathe  would  be  required ;  ordinarily  the  hiring  of  one  should 
be  practicable  and  expedient.  Where  only  built  or  cast 
shapes  were  attempted,  the  wheel  and  its  long  years  of 
drill  might  be  dispensed  with,  and  it  is  possible,  with  strong 
individual  work  of  high  finish  and  fine  quality  and  the 
consequently  restricted  output,  that  an  oil  or  gas  kiln 
would  give  economically  practicable  results.  Between 
the  kiln  for  firing  decoration  simply  painted  on  the  ready- 
made  shape  to  the  full  equipment  here  described  will  be 
found  several  modifications,  but  to  try  the  craft  without 
a  kiln  of  some  sort  is  an  imbecile  proceeding. 

Small  brick  kiln  supplied  with  sag-  Clay :  white,  red,  buff. 

gars. 

Small  muffle  kiln  —  oil  or  gas —  Plaster. 

for  over-glaze  and  lustres. 

Small    enameller's   kiln   for  firing  Glaze  materials. 

quick  trials. 

Kick  wheel,  and  tools  for  throwing.  Oxides,  lustres. 

Clay  bin,  zinc  lined.  Under-  and  over-glaze  colours. 

Damp  box.  Modelling  tools,  callipers. 

Drying  cupboard.  Painter's  outfit. 

Plaster  bin.  Brushes,  straight-edges. 

Pot  boards  and  brackets.  Shellac,  beeswax,  French  chalk. 

Table,  strong  and  heavy.  Gum  arabic  and  tragacanth. 


179 

<Jlaze  tubs,  teak.  Sand  and  flint. 

Sieves,  glaze  and  slip,  Nos.  80,  100,  Spurs,  props,  fire  tiles. 

120.  Tile  boxes. 

Buckets.  Disc  (emery)  for  grinding. 

Bowls,  enamelled  and  earthenware.  Small  pestle  and  mortar. 

Small  porcelain  ball  mill,  hand  or  Jugs  and  funnel. 

power. 

Spray  and  pump  (respirator).  Potter's  knife,  sponges. 

Small  outfit  for  carpentry.  Whirler. 

Files,  sheet  iron,  and  zinc,  wire  and  Turning  tools  and  lathe. 

cutters,  cords,  sandpaper. 

Benches  and  shelves  ad  lib.,  odd  Temperature  indicators. 

cupboards,  chairs,  etc., 

Shovels  and  slicer  for  firing,  tongs  Oil  can,  oil,  waste. 

for  trials. 

Two  large  tubs  and  rubber  tubing.  Callipers  and  compass,  rulers. 

Most  of  this  equipment  has  been  previously  described 
and  needs  no  further  comment. 

The  pot  boards  and  brackets  are  simple  but  indispensable 
devices.  The  boards  are  about  six  feet  long,  iron  shod 
or  cross  battened  to  prevent  warping,  and  six  or  nine 
inches  in  width.  The  brackets  of  any  serviceable  kind 
are  fixed  to  the  wall  at  convenient  distances.  When 
throwing,  turning,  or  glazing,  the  pots  are  stood  on  one  of 
these  boards  to  dry,  and  each  board  as  filled  is  slipped  onto 
the  brackets.  Thus  the  pots  may  be  carried  about  to 
the  kiln,  drying  cupboard,  or  glaze  tubs  without  loss  of 
time  or  frequent  handling. 

The  table  must  be  stout  enough  to  withstand  the  heavy 
work  of  wedging  and  should  have  a  top  of  hard  wood. 
Teak  or  hard-wood  glaze  tubs  have  the  advantage  of 
not  breaking  either  themselves  or  pots  accidentally  knocked 
against  them .  Further,  some  glazes  stick  badly  to  porcelain 
or  enamel  tubs. 


180 

EQUIPMENT  FOR  A  SMALL  POTTERY 

In  the  small  pottery  plotted  here,  the  equipment  and 
arrangement  were  as  follows  : 

An  anthracite  stove  with  the  pipe  running  into  the  large  room 
warmed  the  workshop  in  winter,  but  no  wet  or  half-dry  pots  were  left 
where  the  frost  could  get  at  them. 

The  glaze  materials,  oxides,  colours,  painting  paraphernalia,  finished 
pots,  trials,  and  trial  kiln  were  in  the  small  room.  The  wheel  had  a  good 
top  and  side  light. 

The  drying  cupboard,  plaster  bin,  and  moulds  were  at  the  end  nearest 
the  stove ;  the  clay  bin,  damp  box,  and  sink  farthest  away. 

All  the  walls  were  copiously  supplied  with  brackets  and  shelves  and 
handy  benches. 

Outside,  in  a  well-built  lean-to,  was  the  muffle  kiln  for  onglaze  and 
lustre  decoration. 

This  was  well  bracketed  and  shelved  for  the  biscuit,  and  here  was  done 
the  glazing,  handy  for  packing  in  the  brick  kiln  just  outside.  This  was 
protected  from  the  weather  and  other  lean-to's  held  the  saggars,  coke, 
and  coal. 

EQUIPMENT  FOR  SCHOOLS 

The  teacher  with  ample  funds  and  a  free  hand  will  find 
the  previous  chapter  all-sufficient,  but  in  many  cases  the 
purchase  of  a  kiln  will  nearly  exhaust  the  allowance  and 
the  rest  of  the  equipment  becomes  sketchy. 

The  indispensable  appliances  are  as  follows : 

A  kiln,  with  fire  tiles  or  shelves,  props,  spurs,  and  stilts,  etc.,  for  packing. 
A  good  clay  bin  and  sieve  for  slip  (No.  80)  with  a  tub  and  two  pails. 

Scales  and  weights,  pestle  and  mortar  and  glaze  lawn  (No.  100). 
shot  for  weights. 

Plaster,  for  drying  bats  and  working  discs. 

Large  drip  pan  and  three  round  pans. 

Several  jugs  and  bowls. 

Spoons  (wooden),  knives,  and  big  brushes. 

Oil,  gum,  boards,  strips,  rolling  pin. 

Hammer,  saw,  iron  straight-edge,  sponges. 

Glass  slab  and  muller,  palette  knife  and  brushes  for  painting. 


181 

An  atomizer  or  spray  pump. 
Glaze  materials: 

Kaolin,  China  stone,  flint,  silver  sand,  whiting,  felspar,  borax. 

A  supply  of  ground  pitchers  and  grog,  cones. 
Metallic  oxides : 

Tin,  white,  oxide  of,  iron,  copper,  manganese,  cobalt,  etc. 
Under-glaze  colours  to  taste. 
Glass  jars  with  lids  to  contain  materials.    Gummed  labels,  India  ink. 

For  a  school  in  the  country  or  where  ground  is  available,  a 
kiln  like  the  one  shown  at  p.  164  should  be  practicable.  It 
costs  very  little  to  build  or  to  fire.  Next  comes  the  question 
of  the  clay.  This  is  one  of  the  most  abundant  of  nature's 
materials,  and  almost  any  river  bank  or  creek  will  supply 
clay  of  some  kind.  Any  sort  of  clay  near  to  hand  should  be 
thoroughly  tested  before  going  to  other  or  distant  sources. 

The  clay  should  be  dried,  then  broken  up  with  a  hammer, 
and  mixed  with  water,  and  the  resultant  "  slurry  "  passed 
through  a  sieve  (No.  80).  The  slip  is  allowed  to  settled 
and  the  water  siphoned  off.  The  thick  slip  is  then  dried  on 
the  plaster  bats  until  stiff  enough  to  work  up  between  the 
hands.  From  this  clay  a  tile,  a  plate,  and  a  vase  should 
be  made  and  fired.  If  the  pieces  stand  a  fire  of  about 
1100°  (cone  .03)  without  buckling,  splitting,  or  crum- 
bling, the  clay  should  do  quite  well  for  school  work. 
Possibly  when  screened  fine  enough  for  working,  the  clay 
may  be  too  rich  or  long  and  will  split  at  a  moderate  fire. 
Then  the  screenings  might  be  pounded  in  the  mortar, 
passed  through  the  sieve,  and  added  to  the  slip.  Again, 
ground  pitchers,  fine  grog,  kaolin,  or  calcined  flint 
could  be  tried  as  stiffening  agents.  In  the  unlikely  event 
of  the  clay  being  too  refractory  or  short,  a  portion  of  rich, 
fusible,  or  fat  clay  might  be  added,  or  the  addition  of 
powdered  spar  tested.  (See  chapter  on  Clays.)  The 
colour  of  the  body  will  hardly  matter  for  schools ;  indeed 


182 

a  brown,  red,  or  cane-coloured  clay  will  give  better  results 
than  a  staring  white  paste,  when  working  out  simple 
school  problems. 

Where  necessary,  tin  glaze  could  be  used  for  a  white 
ground,  or  an  engobe ;  that  is,  a  dip  of  white  clay  slip  over 
the  coloured  body.  For  glazing,  a  leadless  glaze  is  strongly 
to  be  advised.  Lead  is  often  indispensable  to  the  crafts- 
man, and  with  care  need  not  become  a  danger;  but 
in  schools  a  lead  glaze  is  positively  harmful. 

A  glaze  with  a  borax  base,  if  ground  dry  and  mixed  with 
water  and  reground  before  sieving,  will  give  little  trouble  if 
used  immediately.  It  will  answer  for  all  grade  work  and 
may  be  used  for  spraying,  dipping,  pouring,  or  painting, 
with  absolute  safety. 

The  ground  pitchers  and  grog  mayv  be  obtained  by 
pounding  up  broken  biscuit  and  pieces  of  fire  tile,  respec- 
tively. This,  and  the  glaze  grinding,  is,  of  course,  laborious 
work,  and  suggests  correlation  with  the  Physical  Education 
Department.  The  drip  pan  and  the  round  tins  make  ex- 
cellent moulds  for  casting  drying  bats  and  working  bats. 

For  casting  purposes  plates  and  shallow  bowls  may  be 
moulded  in  one  piece  as  described,  p.  26.  If  no  lathe  be 
handy,  glazed  vases  may  be  used  as  substitutes,  the 
"  waste  "  being  added  in  plasticine  to  the  neck  and  base. 

For  tile  making,  strips  nailed  on  a  stout  board  will 
serve  in  place  of  tile  boxes.  The  clay  is  rolled  out  on 
cheesecloth  with  a  rolling  pin.  Various  other  expedients 
for  drying  cupboards,  damp  box,  etc.,  will  suggest  them- 
selves as  the  course  develops. 

The  above  equipment  need  not  be  very  costly.  With 
it  the  students  should  be  capable  of  producing  all  kinds 
of  tiles,  built,  pressed,  and  cast  shapes,  decorated  in  relief, 
with  inlays  or  in  colours  or  glaze. 


183 


SIMPLE   RAW  GLAZES.     COLOURLESS 


No. 

MATERIALS 

PARTS 

SIEVE  No. 

CONE 

METHOD  OF  USING 

I 

Lead  oxide,    red 

50 

100.  Mesh 

.03 

Applied  evenly 

Glossy 

China  stone  . 
Flint    .     .     .     . 

30 
10 

with  a  brush  to 
the  green  shapes. 

Fired  very  slowly. 

E  arthenwar  e 

body. 

II 

Borax  .... 

70 

80.  Mesh 

2 

Green     shapes 

China  clay     .     . 

10 

dipped    thick 

Glossy 

Felspar     .     .     . 

75 

and  slowly  fired. 

Flint    .... 

20 

Stoneware  body. 

Whiting    .     .     . 

25 

III 

Borax  .... 

360 

100.  Mesh 

.03 

Ground  dry  for 

Silver  sand    .     . 

160 

£  hour.    Wet  for 

Glossy 

China  clay     .     . 

120 

l£.     Used  when 

Whiting    .     . 

20 

fresh    on   biscuit 

Flint    .... 

10 

(earthenware 

body)  for  under- 

glaze  painting. 

IV 

Lead  carbonate 

130 

80.  Mesh 

.04 

Used  with  me- 

Calcined kaolin 

150 

tallic    oxides    for 

Glossy 

Flint    .... 
Felspar      .     .     . 

50 
50 

simple  colours  on 
earthenware 

Whiting    .     .     . 

10 

body  ;  both  green 

Zinc  oxide      .     . 

10 

and  biscuit. 

V 

Lead  carbonate 

375 

120.  Mesh 

.04 

Used  thick  on 

Kaolin       .     .     . 

210 

hard  white  earth- 

Matt 

Felspar     .     .     . 
Flint    .... 

175 
120 

enware    (CC) 
body. 

Whiting    .     .     . 

105 

Zinc     .... 

25 

184 


SIMPLE  RAW  GLAZES.    COLOURLESS.  —  Continued 


No. 

MATERIALS 

PARTS 

SIEVE  No. 

COKE 

METHOD  or  USING 

VI 

Lead  carbonate 

120 

100.  Mesh 

.02 

Used  thick  on 

China  clay     .     . 

50 

stoneware    body. 

Matt 

Felspar     .     .     . 

80 

Coloured  with  3 

Flint    .... 

15 

to  7  per  cent  of 

Whiting    .     .     . 

45 

glaze    stains    or 

U.  G.  colours. 

The  proportion 

of  lead  and  whit- 

ing may  be  va- 

ried     as     found 

expedient. 

vn 

Borax  .... 

70 

Used  with  va- 

Lead carbonate 

800 

rious  combina- 

Enamel 

China  clay     .     . 
Felspar     .     .     . 

50 
120 

80.  Mesh 

.07-.05 

tions    of    cobalt 
oxide,    copper 

Lynn  sand     .     . 

50 

oxide,    and    iron 

Tin      .... 

40 

oxide  and  copper 

carbonate,  giving 

wide   range  of 

blues  and  greens. 

On    stoneware 

body. 

All  the  above  colourless  glaze  masses  may  be  coloured  with  combi- 
nations of  the  various  metallic  oxides,  or  from  3  to  7  or  even  10  per 
cent  of  glaze  stains  or  underglaze  colours. 


APPENDIX  II 

GLOSSARY 

Alumina,  or  Oxide  of  Aluminium,  is  one  of  the  most  abun- 
dant of  earths.  Combined  with  silica  it  is  the  chief 
constituent  of  kaolins  and  China  clays.  It  imparts 
refractory  qualities  to  clays  and  is  an  indispensable 
ingredient  of  pure  glazes.  Pure  alumina  or  calcined 
Aluminium  is  a  chemical  product. 

Ammonia.  —  A  volatile  gaseous  matter,  found  in  some 
clays.  Alkaline  in  action. 

Antimony.  —  A  silver-white  metallic  element,  used  with 
other  oxides  as  a  colourant  or  to  give  opacity  in 
glazes. 

Arsenic.  —  A  non-metallic  volatile  element,  used  in 
glaze  making. 

Barytes.  —  A  heavy  spar  used  with  clays  to  introduce 
density  and  vitrescence. 

Bauxite.  —  A  very  aluminous  earth,  used  in  preparation 
of  pure  alumina  and  to  render  clays  refractory. 

Boracic  Acid.  —  The  natural  and,  usually,  impure  prod- 
uct (boric  acid  being  free  from  chemicals). 

Borax.  —  The  combined  chemical  product  of  soda  and 
boracic  acid.  Used  as  a  strong  flux  in  glazes. 

Calcined  Bones.  —  The  residuum  of  burned  bones,  used 
to  stiffen  artificial  porcelain. 

Calcined  Kaolin.  —  Kaolin  after  it  has  been  subjected 

to  heat  to  drive  off  the  water  combined  with  it. 

185 


186 

Calcium  Carbonate  (Whiting).  —  Found  as  a  white 
rock,  and  ground  to  pure  powder.  Used  with  clays 
for  soft  bodies.  Gives  durability  to  glazes. 

Calcium  Oxide  (Lime). — A  widely  distributed  earthy 
matter.  Imparts  fusibility  to  clays,  in  nearly  all  of 
which  it  is  present  in  varying  proportions. 

Chrome,  Oxide  of.  —  Used  in  making  greens,  browns,  and 
blacks.  Stands  a  high  fire. 

CLAYS: 

Ball  Clay.  —  Blue  and  black.  Very  plastic  clays.  Used 
with  non-plastic  materials,  such  as  flint,  stone, 
felspar,  or  whiting,  to  form  fine  earthenwares. 

Cane  and  Red  Clays.  —  Clays  coloured  by  the  presence 
of  ferric  oxide,  and  used  extensively  for  bricks, 
terra-cotta  tiles,  and  common  pottery. 

China  Clay.  —  A  yellowish-white,  non- vitreous  clay,  prod- 
uct of  the  decomposition  of  granitic  or  felspathic 
rocks.  Cornish  China  clay  is  exceptionally  white,  pure, 
and  plastic.  It  is  widely  used  with  China,  or  Corn- 
wall stone  and  calcined  bones,  to  make  bone  porcelain. 
Felspar  is  added  to  render  it  vitreous.  Mixed  with 
ball  clays,  pipe  clays,  flint,  and  stone,  it  makes  the 
various  classes  of  earthen  and  stone  wares. 

Pipe  Clay.  —  A  very  white,  smooth  clay.  Less  plastic 
than  ball  clays.  Much  used  for  making  slips,  en- 
gobes,  and  enamels. 

Saggar  Clays  or  Fire  Clays.  —  Coarse  refractory  clays 
strengthened  by  the  addition  of  grog,  used  for  saggars, 
fire  tiles,  and  bricks. 

Cobalt  Oxide.  —  The  oxide  of  the  steel-grey  hard  metal. 
Extremely  valuable  in  pottery,  making  all  shades  of 
blue  for  under-glaze  printing  or  staining.  With 
iron  or  copper  gives  blue-greens. 


187 

Copper,  Oxides  of,  and  Carbonate.  — -  Red,  green,  and 
black  oxides  of  copper  have  been  of  the  utmost 
value  to  potters.  They  are  used  to  produce  green, 
blue,  turquoise,  red,  and  crimson.  Its  extraordinary 
changes  in  reducing  or  oxidizing  fires  are  of  the 
greatest  interest  to  the  experimenter. 

Cornish  or  China  Stone.  —  A  rock  composed  of  felspar 
and  quartz.  Its  vitrification  (about  1400°  C.)  im- 
parts hardness  and  density  to  China  clays.  It  is  a 
valuable  constituent  of  glazes.  First  known  as 
"  moorstone  "  or  "  growan." 

Earthy  Colourants.  —  Rarely  used  in  modern  commercial 
pottery,  except  for  salt-glazed  jars,  crocks,  and 
peasant  pottery. 

Felspar.  —  A  fusible  rock  found  almost  pure  or  in  combina- 
tion with  potash  and  soda,  the  greater  the  percen- 
tage of  alkalies  the  more  fusible  being  the  spar.  It 
is  used  to  replace  more  refractory  materials  in  clay 
and  to  stiffen  glazes. 

Flint.  —  A  pure  silica  with  slight  traces  of  calcium. 
Found  in  pebble  form  on  seashores.  Calcined  and 
ground  to  a  white  powder,  it  is  widely  used  to  impart 
whiteness  and  strength  to  clays.  Invaluable  for 
bedding  and  packing  in  kilns.  Used  with  the  fluxes,  — 
lead,  borax,  potash,  and  soda,  —  to  make  glazes  and 
glass. 

Fluorspar.  —  A  combination  of  fluorine  and  calcium, 
more  fusible  than  felspar,  and  of  a  white  colour, 
felspar  being  pink. 

Galena.  —  Lead  sulphide,  a  highly  poisonous  material 
used  on  "  peasant  "  pottery,  giving  a  soft,  yellowish, 
transparent  glaze. 

Gold.  —  Used  in  solution  for  delicate  purples  and  lustres. 


188 

Gypsum.  —  When  calcined  gypsum  becomes  plaster  of 
Paris,  these  two  materials,  together  with  the  allied 
marble,  limestone,  and  alabaster,  are  widely  used  in 
pastes  (such  as  Parian),  slips,  engobes,  and  variously 
to  impart  fusibility  or  colour  properties  to  glazes. 

Iron,  Oxides  of.  —  Have  a  wide  range  of  colour,  from 
yellow  to  purple.  They  are  used  to  stain  glazes 
and  colour  bodies.  They  impart  fusibility  to  clays 
and  are  carefully  excluded  from  fine  white  bodies. 

Kaolin.  —  A  fine,  white,  very  pure,  and  infusible  China 
clay,  almost  pure  alumina  and  silica.  Chiefly 
used  in  the  manufacture  of  porcelain  and  fine  earth- 
enware. 

Lead  (Oxides  and  Carbonates  of).  White  Lead,  Red 
Lead,  Litharge.  —  Are  very  widely  used  as  a  safe 
and  cheap  flux.  Poisonous.  It  cannot  be  used  in 
those  glazes  that  have  to  stand  a  high  fire. 

Lime.     (See  Calcium.) 

Lynn  Sand.     (See  Quartz  Sand.) 

Magnesia.  —  A  white  metallic  element  present  in  small 
quantities  in  most  clays. 

Manganese.  —  The  black  and  brown  oxides  of  this  hard 
metal  are  much  used  to  stain  slips  and  bodies,  and  to 
colour  glazes  brown  or  purple. 

Marls.  —  Amorphous  deposits  of  lime,  sand,  and  clay, 
very  coarse  in  texture.  Used  in  making  saggars, 
drain  pipes,  and  similar  appliances. 

Nickel.  —  A  hard  metallic  element,  the  oxides  of  which  are 
found  useful  in  preparing  blacks,  greys,  and  greens. 

Nitre  or  Potassium  Nitrate,  or  Saltpetre.  —  A  vitreous 
and  aqueous  compound,  used  in  some  glazes. 

Plaster  of  Paris.     (See  Gypsum.) 

Potash.  —  Potassium  carbonate  or  the  leached  ashes  of 


189 

plants.  Used  from  earliest  times  as  a  powerful  alka- 
line flux. 

Potash,  Bichromate  of.  —  Used  for  pinks  and  crystal- 
line effects.  Poisonous. 

Quartz  or  Quartz  Sand.  —  Like  Lynn  or  silver  sand. 
This  mineral  is  pure  silica  and  free  from  lime,  al- 
though the  sands  may  contain  some  small  percentage 
of  iron.  Used  much  like  flint  for  bedding  or  with 
alkaline  fluxes  for  the  finest  glazes. 

Rutile.  Oxide  of  Titanium.  —  Used  variously  to  im- 
part a  yellow  tinge  to  porcelain,  and  colour  and 
irregularity  to  some  glazes. 

Salt.  —  Sodium  chloride.  Sometimes  used  in  glazes, 
but  best  known  in  connection  with  salt  glazing.  It 
vaporizes  at  about  1200°  C.,  forming  a  silicate 
or  hard,  thin  skin  of  glaze  over  the  clay. 

Silica.  —  A  hard,  colourless  crystalline  element ;  found 
pure,  as  in  quartz,  or  in  combination  with  alumina 
and  alkalies,  as  in  all  clays.  Present  in  all  glazes. 

Soda.  Sodium  Carbonate.  —  Product  of  the  decomposi- 
tion of  salts  with  acids.  It  is  a  strong  alkaline  flux 
and  much  used  in  glaze  and  glass-making. 

Silver  Sand.     (See  Quartz.) 

Tin,  Oxide  of.  —  Used  from  the  earliest  times  to  impart 
opacity  to  glazes. 

Tincal.     (See  Borax.) 

Titanium.     (See  Rutile.) 

Whitening.     (See  Lime.) 

Zinc,  Oxide  of.  —  A  white  metallic  oxide ;  used  to 
brighten  and  stabilize  glazes  and  colours. 


190 


POTTER  8   TERMS 

Bags.  —  Chimneys  or  walls  of  fire  bricks  built  to  protect 
the  ware  from  flame. 

Baitings.  —  The  feed  of  fuel  during  firing. 

Bat.  —  Any  flat  slab  of  plaster,  biscuit,  or  fire  clay. 

Biscuit.  —  The  fired  but  unglazed  clay. 

Blowing.  —  The  shattering  of  the  clay  shape  when  biscuit- 
ing.  Usually  due  to  hurried  firing  or  the  sudden  access 
of  heat,  and  the  consequent  generation  of  steam. 

Blunger.  —  A  machine  for  mixing  clay. 

Bungs.  —  Piles  of  filled  saggars. 

Chuck  or  Chum.  —  The  cone  or  cap  used  to  support 
shapes  during  turning  on  the  lathe. 

Clamming.  —  The  wet  marl,  sand,  or  siftings  applied  to 
cracks  in  the  hatches  or  doors  of  kilns  to  retain  the 
heat  during  firing. 

Craze.  —  The  minute  cracks  that  appear  in  a  badly 
fitting  glaze.  When  arrived  at  by  design,  as  in  some 
Chinese  work,  it  is  termed  a  crackle,  but  there  is  then 
no  fissure. 

Drawing.  —  Unpacking  the  kiln  after  firing. 

Engobe.  —  A  dip  or  outer  covering  of  slip ;  usually  ap- 
plied to  inferior  bodies  to  improve  their  appearance. 

Fat.  —  Clays  that  are  sticky  or  greasy  are  sometimes 
termed  fat  by  potters. 

Fettle.  —  To  touch  up,  and  remove  traces  of  seams,  cast 
lines,  etc. 

Fluxes.  —  Those  materials  which  by  their  addition  to 
paste  or  glaze  render  them  fusible,  although  they 
may  not  always  be  fusible  themselves. 

Glost.  —  The  glazed  ware,  usually  applied  to  the  glaze 
in  firing,  as  glost-oven. 


191 

Green.  —  The  clay  shapes  before  biscuiting. 

Jigger.  —  The  wheel  on  which  shapes  are  moulded  with 
the  aid  of  a  jolley  or  profile. 

Joggle.  —  The  natch  or  key  in  a  mould  to  insure  correct 
adjustment  and  prevent  slipping. 

Lawn.  —  The  fine  mesh  gauze  through  which  glazes  are 
strained. 

Long.  —  A  clay  is  termed  long  if  very  ductile  and  tena- 
cious. 

Muffle.  —  Usually  the  fire-clay  box  or  interior  of  a  small 
kiln,  but  applied  to  any  kiln  to  the  inside  of  which 
the  flames  have  no  access. 

Natch.     (See  Joggle.) 

Oxidizing.  —  The  ordinary  method  of  firing  gives  an 
atmosphere  in  which  there  is  always  sufficient  oxygen 
to  consume  all  the  carbon  or  combustible  gases. 
If  oxygen  is  present  in  excess,  it  causes  reactions 
known  as  oxidizing. 

Pitchers.  —  Finely  ground  biscuit.  Added  to  some  clays 
to  increase  refractories  or  porosity.  Moulds  made 
in  such  clays  and  fired  are  termed  pitcher  moulds. 

Potsherds.  — Any  broken  biscuit  or  pot,  sometimes  used 
for  pitchers. 

Potting.  —  A  colloquialism  used  to  designate  the  ceramic 
industry. 

Pugging.  —  The  roll  of  infusible  clay  placed  between  each 
saggar  when  building  bungs. 

Reducing.  —  The  reaction  that  accompanies  the  intro- 
duction of  smoke  or  gas  containing  carbon  in  a  very 
finely  divided  state  into  a  kiln  during  the  process 
of  firing  glaze.  Reduction  is  now  widely  employed 
in  obtaining  fine  lustre  effects. 

Refractory.  —  Hard,  infusible. 


192 

Rich.  —  Used  of  clays  that  are  long  and  fusible,  such  as 

red  clays. 

Riffle.  —  A  grooved  and  toothed  plaster  tool  of  steel. 
Saggars.  —  Or  seggers.     The  fire  clay  receptacles  in  which 

the  glazed  ware  is  set  during  the  firing. 
Setters.  —  Supports   used  when   packing  friable  biscuit. 
Short.  —  A  word  used  to  denote  a  clay  that  crumbles  or 

is  difficult  to  pull  up  on  the  wheel. 
Sieve.  —  Sometimes   called   a   lawn,    more   correctly   a 

screen  for  clay  or  slip. 
Slip.  —  The  sieved  clay  or  paste  in  creamy  liquid  condition 

as  used  for  slip  decoration,  engobes,  or  casting. 
Slub  or  Slurry.  —  Clay  mixed  with  water  but  not  sieved, 

as  with  slip. 
Spy.  —  The   small   hole,   kept  plugged,   through   which 

tests  and  cones  are  observed. 
Stunt.  —  Or  dunt.     To  crack  or  split  on  cooling. 
Turning.  —  The  shaving  down  of  the  clay  shape  on  a 

lathe,  to  impart  lightness  and  finish. 
U.  G.  —  Under-glaze  (applied  to  colours). 
Vent.  —  A  hole  to  aid  the  even  distribution  of  fire  in 

a  kiln  or  to  accelerate  the  cooling  off. 
Waster.  —  Commercially,  a  spoiled  pot ;    defective  ones 

are  termed  "  seconds." 
Wedging.  —  The  beating  or  slamming  operation  usually 

employed  to  expel  air  or  correct  inequalities  just 

before  clay  is  used  by  the  thrower. 
Whirler.  —  A   circular   support   pivoting   on   its   centre, 

used  in  casting  or  banding;    similar  to  a  banding 

wheel,  but  usually  heavier. 


193 

MATERIALS,   TERMS,   ETC. 


SYMBOL 

C  -  COM- 
BINING OR 
E  —  EQUIV- 
ALENT 
WEIGHT 

FUSING  POINT 

Alumina  (calcined) 
Alumina  (hydrated)     . 

A1203 
A12O3  •  3  H2O 

C  102  1 
C156  J 

Very  infusible 

Aluminium     .... 

Al 

E27 

627°  C. 

Ammonia        .... 

NHs 

Volatile 

Antimony       .... 

Sb 

E120 

432°  C. 

Antimony  oxide  .     .     . 

SbO 

Arsenic       

As 

E75 

500°  C. 

Barium    (metallic   ele- 

Ba 

E137 

Fuses        above 

ment)      ..... 

red  heat 

Barium  carbonate    .     . 

BaCO, 

C197 

Barytes           .     . 

BaSO4 

C233 

Fuses        about 

white  heat 

Bauxite      

Bismuth     

Bi 

E28 

Borax  (crystals)  .     .     . 

Na2B4O7  •  10  H2O 

C382 

Very  fusible 

Boric  acid  (crystals)     . 

BjO3  •  3  H2O 

C124 

Boric  acid  (dry)       .     . 

B20S 

C70 

High        fusing 

Boron     (metallic     ele- 

B 

Ell 

point 

ment)      

Calcined  bones         .     . 

Infusible 

Calcined  kaolin    1 
China  clay  (fine)  /  ' 

AL2O3-2SiO2 

C222 

Very    infusible, 
slightly     vit- 

reous          at 

highest      fire 

Calcium  oxide  (lime)    . 

CaO 

C56 

Very        refrac- 

tory if  alone 

but      fusible 

with  clays 

Calcium  carbonate 

CaCO3 

C100 

China  stone     I  ... 
Cornish  stone  J 

SSiCfe  •  2A12O3  •  KaO 

1379 

1300°  C.  about 

Chrome  oxide      .     .     . 

CraOs 

C79 

Chromium      .... 

Ca 

E51 

Above       plati- 

num 

Cobalt        

C« 

E59 

1500°  C. 

194 


MATERIALS,   TERMS,   ETC.  —  Continued 


SYMBOL 

C  -  COM- 
BINING OB 
E  -  EQUIV- 
ALENT 
WEIGHT 

FUSING  POINT 

Cobalt  oxide       .     .     . 
Cobalt  oxide  (black)    . 
CoDDer 

Corf), 

0*04 

Cu 

C165 
C240 
E63 

1054°-1084°  C. 

Copper  oxide  (black)   . 
Earthy  colourants 
Ochres 
Siennas 
Umbers 
Felspar      

CuO 
6  SiOj  •  Al,Oi  •  KK) 

C70.5 
C556 

1200°-1300°C. 

Flint  (calcined)   .    .    . 
Fluorspar        .... 

Galena  (lead  sulphide) 
Gold 

SiO, 
CaF, 

PbS 
Au 

C60 
E  147 

about,        ac- 
cording      to 
purity 
1830°  C.  about 
Much        lower 
than          fel- 
spar 
Very  fusible 
1054°-1075°  C 

Gypsum       (plaster  of 
Paris,  if  calcined)     . 

CaS04  •  2  H,0 
Fe 

C17S 
E56 

1530°-1600°  C 

Iron  oxide       .... 
Iridium 

Ferf), 
jr 

C160 
E  193 

about 
1950°  C   about 

Kaolin    (see    calcined 
kaolin)     .... 
Lead  (metal)  .    .     . 
Lead  carbonate  .     . 
Lead,  red  oxide  of  . 
Lime  (see  calcium  ox 
ide  or  carbonate)     . 
Lynn  sand  (see  silver 
sand)       
Magnesia  (calcined)     . 
Magnesia  (carbonate) 
Manganese,  carbonate 

AUOj-SSiOj-i-HiO 
Pb 
PbCO, 
Pb,04 

CaO 

SiO, 
MgO 
MgO-COj 
MnCO, 

C258 

K  *IHJ 

C40 
C115 

Infusible 
326°  C. 

430°  C. 

195 


MATERIALS,   TERMS,    ETC. —Continued 


SYMBOL 

C  =  COM- 
BINING OR 
E  =  EQUIV- 
ALENT 
WEIGHT 

FUSING  POINT 

Manganese  (metal) 

Mn 

E55 

1670°  C.  about 

Manganese    oxide    (or 

black)     

MnO2 

C87 

Nickel  (metal)     .     .     . 

Ni 

E58 

1427°-1450°  C. 

Nickel  oxide        .    .    . 

NiO 

C75 

Nitre     

KNOs 

Pearl  ash  or  potash 

KOH 

Plaster   of   Paris    (cal- 

cined gypsum)      .     . 

CaS04-iH20 

C145 

Platinum         .... 

Pt 

E197 

1710°-1775°  C. 

Potash,  bichromate  of 

K2Cr2O7 

Fuses   dull  red 

heat 

Potassium  carbonate    . 

KsCOs 

C138 

Potassium  oxide       .     . 

KaO 

C94 

Quartz            ) 
Quartz  sand  J 

SiO2 

C60 

1830°  C.  about 

Rutile  (see  titanium)    . 

Salt        ...... 

NaCl 

776°  C. 

Silica     

SiOa 

C60 

Silver  sand  (or  quartz 

sand)       

SiO2 

Silver  (metal)      .     .     . 

Ag 

E107 

945°-962°  C. 

Soda  ash  (calcined) 

Na2CO3 

C106 

Soda  crystals       .     .     . 

Na2CO3.10H2O 

C286 

Sodium  oxide      .     .     . 

Na20 

C62 

Tincal  (see  borax) 

Tin  (metal)     .... 

Sn 

E119 

233°  C. 

Tin  oxide  (white)     .     . 

SnO2 

C150 

Titanium  oxide  (rutile) 

TiO2 

Infusible 

Uranium  (metal)      .     . 

U 

E239 

1800°  C.  about 

Uranium,  oxide  of 

U308 

Whitening     (see     lime 

carbonate)        .     .     . 

Zinc  (metal)         .     .     . 

Zn 

E65 

443°  C. 

Zinc  oxide  (white)    .     . 

ZnO 

C81 

196 


SEGER  CONES.    (STANDARD  CONES.     ABOUT  10°  HIGHER.) 

NUMBERS.     TURNING  POINTS.     COLOUR,  ETC. 

APPROXIMATE 
DEGREES  or 

COLOUR  IN  KILN      CONK        HEAT  AT  WHICH  MATERIALS  SUITABLE  TO  BE  FIRED 
NUM-          CONE  TURNS  AT  THESE  TEMPERATURES 

BER  OR  BENDS  (APPROXIMATE) 


Centigrade 

Commences  to     f'J» 
show  colour     \m                   670o 

L  Soft      enamel     or     over-glaze 
colours. 

.019                   690° 

Dull  red 

.018                   710° 
.017                   730° 
.016                   750° 

Enamels     on     metals.     Fluxes 
and  lustres. 

.015                   790° 

.014 

815° 

Red  to  cherry     4 

.013 
.012 

835° 
855° 

Very    soft    glazes    and     hard 
enamel        colours.        Some 

.011 

880° 

lustres.     Gilding. 

.010 

900° 

.09 

920° 

.08 

940° 

.07 

960° 

Dull  cherry  to 

.06 

980° 

Majolica    glazes    or    coloured 

light  cherry 

.05 

1000° 

glazes  and  stanniferous  or  tin 

.04 

1020° 

glazes. 

.03 

1040° 

.02 

1060° 

Earthenware       glazes.        Soft 

.01 

1080° 

China  glazes. 

1 

1100° 

Dark  orange  to 
pale  orange 

i 

2 
3 

1  Jww 

1120° 
1140° 

Soft  to    hard  or  fine  earthen- 
ware biscuit. 

4 

1160° 

5 

1180°     Sevres  soft  bisque. 

Yellowish  white 

6 

7 
8 

9     o  1  Vitreous  ware.     Granite  ware. 
11250°]      S*11  «***«•    Stoneware. 

9 

1280°     English  bone  porcelain  or  China 

10 

1300°         biscuit 

White                  4 

1  1 

1320° 

Intense  white 

12]              [1350°  } 
13  1            1  1380°   (  German  and  Chinese  porcelain. 

14  J               1410°      Sevres  porcelain. 

197 


SEGER  CONES.    (STANDARD  CONES.    ABOUT  10°  HIGHER.) 

NUMBEBS.     TURNING  POINTS.     COLOUR,  ETC. 

APPROXIMATE 
DEGREES  OF 

COLOUR  IN  KILN     CONE       HEAT  AT  WHICH  MATERIALS  SUITABLE  TO  BE  FIBED 
NUM-  CONE  TURNS  AT  THESE  TEMPERATURES 

BER  OR  BENDS  (APPROXIMATE) 

Centigrade 
15  1430° 


Bluish  white         f  16  1  1460° 

117  J 


1480°  Copenhagen  porcelain. 

To  convert  temperatures : 

Centigrade  into  Fahrenheit.  —  Divide  by  5,  multiply  by  9,  and  add  32. 

Fahrenheit  into  Centigrade.  —  Subtract  32,  divide  by  9,  and  multiply 
by  5. 


MEASURES,  WEIGHTS,  ETC. 

APOTHECARIES 

1  grain      =  .0648  gramme. 
20  grains       =  1  scruple  =  1.296  grammes. 
3  scruples    =  1  drachm  =  3.888  grammes. 
8  drachms  =  1  ounce     =  31.103  grammes. 

TROT 

1  grain  =  .0648  gramme. 

24  grains  =  I.  penny  weight  =  1.555  grammes. 
20  pennyweights  =  1  troy  ounce      -  31.1035  grammes. 

AVOIRDUPOIS 

16  drams  =  1  ounce. 
16  ounces  =  1  pound. 
14  pounds  =  1  stone. 
28  pounds  =  1  quarter. 
112  pounds  =  1  hundredweight  (cwt.). 
20  hundredweight  -  1  ton  (2240  Ibs.). 


198 

CAPACITY  (WET) 

1  gill  =1.42    decilitres. 

4  gills  -  1  pint  -  .568  litre. 

2  pints  -  1  quart  -  1.136  litres. 

4  quarts  -  1  gallon  -  4.545  litres. 

2  gallons  =  1  peck  -  9.09    litres. 

4  pecks  -  1  bushel. 

8  bushels  -  1  quarter. 


BOOKS  OF  REFERENCE 

TECHNICAL 

Chemistry  of  Pottery.     Langenbeck,  Karl. 
^  Chemistry  of  Pottery.     Shaw,  Dr.  S. 

Clays.     Occurrences,  Properties,  and  Uses.     Ries. 

Colouring  and  Decorating  of  Ceramic  Ware.     Brongniart,  A. 

Ceramic  Technology.     Binns,  C.  F. 

Notes  on  the  Manufacture  of  Earthen  Ware.     Sandeman,  E.  A. 

Notes  on  Pottery  Clays.     Fairie,  Jas. 

Pottery  Decoration.     Hainbach,  R. 
TECHNICAL  AND  HISTORICAL 

Leadless  Decorative  Tiles.  "I  _, 

,  _  .      .  }  Furnival,  W.  J. 

Faience  and  Mosaic,  and  other  volumes.  J 

MANUAL 

Pottery.     I. mm.  Richard. 

Grand  Feu  Ceramics.     D'oat,  Tarile. 

The  Potter's  Craft.     Binns,  C.  F. 

Practical  Keramics  for  Students.     Janvier,  C.  A. 
HISTORICAL  AND  ARTISTIC 

Art  of  the  Old  English  Potter.     Solon,  L.  V. 

Chinese  Porcelain.     Gulland. 

Chinese  Porcelain.     Monkhouse,  Cosmo. 

Ceramic  Art  in  Great  Britain.     Jewitt,  L. 

History  of  Pottery  and  Porcelain.     Marryat. 

Majolica.     Fortnum,  C.  D.  E. 


199 


Potters,  Their  Arts  and  Crafts.    Sparkes  and  Gandy. 

Pottery  and  Porcelain  in  the  United  States  (and  other  volumes). 
Barber. 

Persian  Ceramic  Art  (and  other  volumes).     Wallis,  H. 

Illustrated  catalogue  of  the  Faience  of  Persia  and  Near  East.  Bur- 
lington Fine  Arts  Club. 


BISCUIT   SHAPES. 

CHINA  AND  BALL. 


APPLIANCES  AND  MATERIALS,  ETC. 

SOLD  BY 
BALL  MILLS.  Wengers,   Ltd.    Eng.     (Hanley,  Stoke 

on  Trent.) 
Abbey  Engineering  Co.    220  Broadway, 

N.  Y.  City,  U.  S.  A. 
Hirshberg  Art  Co.     Baltimore,  Md. 
Mandle  and   Sant.      East  Liverpool, 

Ohio,  U.  S.  A. 

Stewart  &  Co.    N.  Y.  City,  U.  S.  A. 
Wengers.    Hanley,  Great  Britain. 
Western  Stoneware  Co.     Monmouth, 

Dl.,  U.  S.  A. 
W.   H.    Cutter,    Woodbridge,    N.    J., 

U.  S.  A. 

Wengers,  Ltd.    Hanley,  Eng. 
Drackenfeld  &  Co.     Murray  St.,  N.  Y. 

City,  U.  S.  A. 

Professor  Ed.  Orton.     Columbus,  Ohio. 
Wengers,  Ltd.    Hanley,  Eng. 
Drackenfeld  &  Co.     Murray  St.,  N.  Y. 

City,  U.  S.  A. 
Roessler,     Haslacher     Chemical     Co. 

William  St.,  N.  Y.  City,  U.  S.  A. 
Fletcher,  Russell.    Warrington,  Eng. 
Bellevue    Perfection.     Detroit,   Mich., 

U.  S.  A. 


CLAYS 


CONES. 


CHINA  AND  MODEL- 
LING. 

MODELLING  AND 
STONEWARE 

SAGGAR  AND  STONE- 
WARE. 


GLAZES. 


KILNS.    GAS. 

KILNS.    GAS  AND  OIL. 


200 


KILNS.    OIL. 

KILNS.    TRIAL. 
LAWNS  AND  SIEVES. 


PLASTER. 

QUARTZ,  FLINT,  FELSPAR. 

SCALES. 
STILTS,  ETC. 

U.  G.  COLOURS,  ETC. 
WHEELS. 


Caulkins  Revelation.    Detroit,  Mich., 

U.  S.  A. 

Wengers,    Hanley,  Eng. 
Drackenfeld   &   Co.     50  Murray  St., 

N.  Y.  City. 
A.  Sartorious  &  Co.    Murray  St.,  N.  Y. 

City. 

Wengers.     Hanley  Staffs,  Eng. 
Wengers.     Hanley,  Eng. 
Drackenfeld  &  Co.    N.  Y.  City. 
Calvin  Thompkins.    Battery  PI.,  N.  Y. 

City. 

Wengers,  Ltd.    Hanley,  Eng. 
Drackenfeld  &  Co.    Murray  St.  N.  Y. 

City,  U.  S.  A. 
Golding   &   Sons.     Trenton,    N.    J., 

U.S.  A. 

Wengers.    Hanley  Staffs,  Eng. 
Hy.    Troemner.       Philadelphia,    Pa., 

U.S.  A. 
Trenton  Stilt  &  Spur  Co.    Trenton, 

N.  J.,  U.  S.  A. 
Wengers.    Hanley,  Eng. 
Wengers.     Eng. 

Drackenfeld  &  Co.   N.  Y.  City,  U.  S.  A. 
Crossley   Mfg.  Co.    Trenton,    N.   J., 

U.  S.  A. 
T.  S.  Nickerson.    Newburyport,  Mass., 

U.  S.  A. 


THE  ARTISTIC  CRAFTS  SERIES 
OF     TECHNICAL     HANDBOOKS 


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m 


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'P  LJ 


MOV  a  7 

FOR* 


LD 


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|...-      • 


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'64-8  AM 


LD  21A-50m-4,'60 
(A9562slO)476B 


General  Library 

Unirersity  of  California 

Berkeley 


^ !  j     1 


)F   CALIFORNIA          LIBRARY    if  iK       .    OF    CALIFORI 

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3F    CALIFORNIA          LIBRARY    OF   THE    UNIVERSITY   OF    CALIFOR 


